First, even if it doesn't feel like it, it's really good that you're able to take that objective view of your work and understand that you're on a trajectory. It's really common that artists can't really look past a current obstacle to get a larger idea of the map, so to speak, and then get so discouraged that they can't bring themselves to try. You're at a point that can be so, so frustrating, and I'm sure everyone here can sympathize.
As for a way to meaningfully approach those obstacles, it sounds like you're just a hop and a skip from the next logical step to climbing that hill: eliciting constructive advice from communities like this one. Speaking for myself, I generally come back to these forums when I have a piece that I'm really stuck on and I'm getting in my head about it and I need some objective eyes that can help me identify my weaknesses. (Unfortunately this can mean I disappear for very long stretches, oops. Sorry, everyone.) I've never received anything but incredibly helpful, honest feedback from members here, and it's made me a better craftsperson for life.
But also I know sometimes you might be trying to explore things on your own or don't feel like you have a capital-p Piece that you can bring to a group for critique. In those instances, I like to sit down and take really straightforward stock of myself as an artist. For the sake of kindness, I usually start by noting the things I'm proud of and think I do well, and then I move on to the things that I don't think are working. And then I make a list of ways I can specifically address those weaknesses--that can be as ambitious as setting out to hit a big milestone like finishing a project, or as small as wanting to get the knack of drawing more dynamic poses. For smaller components of the process (which is what it sounds like you're working toward) I would recommend seeking out artists who you feel specifically excel at those things; study what works for them, maybe even process videos or streams they make available. If you feel like you have a tendency to get lost in the weeds of working on whichever smaller component that is, then I would recommend setting a goal for finishing a piece that specifically incorporates that element--preferably something with a deadline. That's what I did with mermay this year; I picked a weekly prompt list and assigned each prompt the additional criteria of an exploratory challenge, like character design or color or perspective. Something like an informal prompt list is good because the stakes are pretty low, but you're still accomplishing something.
This turned into a really long reply, sorry. I hope it helps, though, and good luck!