Just straight up murder your inner critic while you’re drawing.
Replace it with Friendly Art Teacher™
“Okay, that’s isn’t working, but there’s a way to fix that”
“Think of all the experience you’ll get from starting over on a section that had a big mistake!”
“It’s okay to let go of things that aren’t working!”
“The end result might be different from your goal, but you can do things that surprise yourself and make yourself like it even better!”
“You should finish your projects, but don’t push yourself so hard that you burn out.”
“And as long as you turn stuff in, maybe the one you’re working on right now isn’t the answer to your assignment. Keep making, you don’t have to keep making this particular drawing though”