Circumstances are different and solutions are different depending on the origin of the problem. Sometimes you really need to force yourself through - finding some kind of trigger that makes you draw regardless of subject or outcome. Sometimes you need to re-focus - then having a project you need to work on, as suggested by @Art-of-B can pull you forward. Sometimes you need to re-kindle inspiration - by taking a trip to a museum or gallery or immersing yourself in visual material or treating yourself to a sketching session at the coffee shop or playground (that´s a reward for me!). Other times you just really need time off. That´s the most difficult for me to admit, but luckily I have my children. They are off-school right now and we normally split care duty in summer between me, my husband, holiday camp and 1-2 week of family holiday. Last week was my week, so I had to completely give up the idea of working during the day. We did day-trips, crafts-days, swimming-pool afternoons, baking, etc... To really and completely give up the idea of work without any sense of guilt - that is rare for me and it´s incredibly refreshing and energizing.
It seems your issue here is self-doubt? You definitely are in good company. In these circumstances, just doing any work doesn’t help me. I need to do something that reminds me that art is a constant process of improvement and not a goal - something that definitely moves me forward. I normally revert to studies: draw 50 hands or learn all the muscles of the arm or learn how the ear is built. I normally study and forget all those things at least once a year, but the process of learning them is always rewarding and motivational for me.
Another thing that helps me is doing master studies. I pick one of my go-to artists (I have 5-6 artists that I constantly study from) and just set out to copy 10 of their drawings. I don’t need to think, I don’t need to design, I can just „sit back“ and let my eye-hand coordination improve a fraction while I reflect on which aspect of the work is catching my attention. Sometimes is the way they shape a face, sometimes is how they design characters. After an hour of that, I invariably end up wanting to apply whatever I learnt to my own work, so the sketches start to be variations rather than copies and then my own sketches. This activity helps me always - comparing yourself to artists you admire is often the trigger for feelings of inadequacy. De-constructing their work makes them more accessible and makes the goal of doing work of comparable quality seem less daunting.
I hope you find a way of getting over this phase - it´s always ugly and it´s always recurrent. I don’t thing there is any person doing creative work who is immune from that.