I assume (potentially falsely, don't get mad if I am wrong pls) that you are adhd or something. if not, I don't know if this will help, but if you are, here are some tips. First off, create a checklist (in google sheets or something) that changes colors. if you get dopamine from drawing, draw out a checklist. for the google sheets, have anything that is not started red, anything currently being worked on as orange yellow, and anything that is finished as just green. if you draw, draw little flowers or rubber duckies or something but DO NOT COLOR THEM. when you finish something, color in the little thing.
ADHD runs on dopamine, so reward yourself with dopamine. I've heard of people who eat a chocolate chip when they finish something. a reward system is what prevents adhd burnout. I had the same issue earlier (link to chat here) and got some feedback. I wish you the best and can't wait to see what you make. If bad comes to worst, make a game you enjoy and publish it on itch anyway. Making a full game outside of a game jam is probably going to be better than making an unfinished game in one.
I hope my rambling helps some.