Wow. At first I thought IBD for sure, but he's holding his head completely level. And he really looks like he's trying to get OUT.

If you can rule out mites, and you can't afford a vet, can you give him a different caging situation? Buy him an all-new, larger tank, use a completely different sort of bedding, give him a bunch of new hides? Because if it's not medical, and your husbandry is fine, that pretty much just leaves environmental.

(Or a girl. I suppose he could really, really want a female--he looks like my horny males when they wrestle. Except they usually wrestle with ANOTHER SNAKE, not by themselves.)