Are you on Twitter (or whatever is left of it?) Art directors often post a call for illustrator with a specific style or subject matter interest. You can then reply with a few images and your portfolio link. Heard some unagented illustrators have gotten work that way 
don't give up, I think your art will find its audience when marketed correctly.
www.instagram.com/art.melc.illo/
www.artmelc.com
I write weekly on mondayblues.substack.com
@Jeremy-Ross Yes, I was going to suggest The Illustration Department! Love this podcast. Guiseppe is bar none sooo super helpful and a rare gem in this business, I have listened to a few interviews with agents, editors, publishers here! Encourages the discouraged artist. And he does a weekly critique group on Thursdays, so helpful. Anyway, thought I'd say this is an avenue I would check out!
@MarcRobinson Holy cow Marc your work is so dang good and consistent all you need is to trust you're at that level and the right ones will be making their way to you.
If I can offer any helpful words, then let these be the ones I hope to share in a way you can take inside and let it resonate. You to me, seem already, like a big fish in a small pond. Your work just stands out. I think I already said once that you remind me of Brandon Dorman, a working illustrator, prolific in the market. He's always working. I know it's a numbers game, for as many submissions and queries, etc. all it takes is just one to bite. So, trust you're on your way and the right situation will be revealed!
There is something to be said of the study of neuroscience and a simple daily practice of saying what you want, at first it is strange and almost silly but you start seeing through different and kinder eyes at yourself, and you can feel the incredible opportunities just waiting to pop.
When I first saw your work I could sense you're closer to what you want than you know. I am waiting to see your post about it! I am already cheering you on.
Erin Richardson
instagram.com/erinrichardsondesigns21
www.erinrichardsondesigns.com
Is anyone else just dying to know what the deleted @davidhohn comment was, or have I just spent too much time on Reddit? 
the site: katherinetyson.com
instagram: instagram.com/katherinetysonart
@Katherine It wasn't a big deal. I realized my "advice" didn't pertain to the original question of agents and styles.
I was just off topic and didn't want to take up space.
But I'll take this moment to say that Marc's work is great. And he's getting great advice from other members!
Hi Marc I think your work is great. I don't have any advice to offer about agents and style but have you considered a portfolio review? Orange Beak Studio are currently offering portfolio reviews for £20 - it's just written feedback but I thought it might help and they know the UK industry.
I hope its OK to suggest a them on here.
I have seen similar style to you in books - The Legend of Podkin One Ear (5 Realms) by Kieran Larwood illustrated by David Wyatt. Chapter books for 8+ year olds. I read them during covid lockdown home schooling!
www.davidwyattillustration.com
Maybe take a look at his website for some more info.
I don't think he does picture books more on the chapter book side.
See also Jonny Duddle www.jonny-duddle.com
@Jeremiahbrown Thanks mate. I appreciate the good vibes. I've not yet tried to get representation, and I'm really grateful for all the advice from you guys. And this is the first time I've ever heard the term "vision holes". I like it.
@kirsten-mcg Thank you Kirsten, I appreciate the kind words. I was definitely concerned when I saw the lack of my style on all of these websites. But like you say, just because it's not on trend, doesn't mean there isn't room for it. It's funny you should mention black and white work, because I was just thinking of adding some inked linework pieces that could fit in the interior of some kids novels. Maybe I'm just getting ahead of myself and psyching myself out. Once I start sending my stuff out in the spring, hopefully it'll all work out. Hopefully your agent will find you some jobs soon, but I'm encouraged by your example of looking for stuff yourself. I admire your entrepreneurial spirit! I have a habit of talking myself out of things, so maybe this time I should have some faith.
@Jeremy-Ross cheers mate. Thanks for the podcast tip, I'll definitely listen to that this week.
@ArtMelC I used to have a Twitter but got rid of it a couple of years ago because I wasn't using it. I'll have to create a new one for my art and see what I can find! thanks for the tip off!
@ArtistErin Thank you. I have to tell myself to have faith things will work out if I keep at it. Thank you for the Brandon Dorman tip off! His stuff is really cool and reassuring that a style similar to mine is getting loads of work. I wish I'd seen his pirate book sooner, because the cover pose would have been helpful for reference ha! Sometimes it can feel that doing something you love for a living is only for other people, but like you say, this isn't the case. Thank you.
@geekinm You know what, I've never thought of a portfolio review. Once I get a few more pieces together I'll have to get on that. Thank you!
@geekinm Now you mention it, I've seen David Wyatt stuff in my local book shop. And I have a couple of Jonny Duddle books somewhere too. For some reason I'd never considered their stuff similar to mine, but I guess you're right. There must be room for my stuff somewhere. Thanks again mate.
@MarcRobinson if you do make a twitter account, don't hesitate to block a lot of accounts/ posts / keywords you don't want to see. The Kidlit community is awesome but the political side of Twitter can be too much for me, so I block things and curate my specifically kidlit and books content on my timeline else I go crazy.
Art directors do actively monitor #kidlitartpostcard hashtags where you post a digital postcard every first Thursday of the month
There are often PB Pitch contests too if you have book dummies to pitch editors.
www.instagram.com/art.melc.illo/
www.artmelc.com
I write weekly on mondayblues.substack.com
@MarcRobinson Certainly! I'm glad to help
@ArtMelC yeah I'm definitely going to have to filter loads of the crap on twitter if I'm going to use it. Thank you for the heads up, I'll have to check out some of these ways into getting the attention of the right people!
@MarcRobinson @Jeremiahbrown @kirsten-mcg @NessIllustration Hey check this out... been messing with making a simple animation. This little Christmas card I made is so simple yet so fun!!! I heard somewhere it's not enough to be making static images. It was on a podcast... 3PP? Can't remember. Anyway, that's another way to stand out as you create your brand as an illustrator. Show little GIFs or shorts, I am thinking cute moving stickers... I mean so much fun.
So thought I'd share this idea, as another way to reach/advertise/build rapport. And, since most people are on their phones with such little attention spans moving images tends to grab people more. That's likely why reels are being pushed so hard on IG, and the conversion rate is higher for that reason?
Erin Richardson
instagram.com/erinrichardsondesigns21
www.erinrichardsondesigns.com
Hi Marc,
I'm just going to echo what everyone else is saying. Your work is superb. I don't think you need to change your style or the subject matter that you are passionate about. People of all ages love to lose themselves in wonderful, rich fantasy worlds and you are one of the rare artists who can create that sort of world very effectively. It's just a matter of getting yourself out there.
In terms of the business side of things, in some ways (even if you get an agent) you need to be your own agent too and find a way to distance yourself emotionally from the work so that you don't feel the rejections too acutely. I've always found that I'm a far better promoter of other people's work than my own - I think it's something many artists need to work on. A lot of the time the people who succeed are the ones who put themselves out there repeatedly and without hesitation or apology. Just have to do it and persist. In your case you've got a solid foundation - the work is great. Portfolio review: good idea but if they are suggesting you change too much, I'd get a second opinion.
It seems like you set yourself very high standards - which is fine but use them to create great work, not to be your own worst critic. All the best with it - can't wait to see what happens next for you.
I have seen similar style to you in books - The Legend of Podkin One Ear (5 Realms) by Kieran Larwood illustrated by David Wyatt. Chapter books for 8+ year olds. I read them during covid lockdown home schooling!
www.davidwyattillustration.com
Maybe take a look at his website for some more info.
I don't think he does picture books more on the chapter book side.
