Maybe play with it in your head a bit more when you have some free time. I definitely can't take on another project right now. I have like 4 I should be working on, lol. Even if you feel like you'd be phoning it in, sometimes it's just as important to finish it. My first projects were roooough (even some of my more recent ones too lol), but I put them out anyway. Provides a source of feedback and reflection. Even if you don't make the deadline of the jam, you really should do it in your free time. Don't pressure yourself on the deadline, especially for a first project. Let it flow when it comes to you.
It might also be helpful to shelf it for a bit, and see if you can get inspired by something else. Letting the project you're hung up on get in the way of something you're inspired on hurts general productivity in both. Strike while the iron's hot n' all that.