My main thesis is ... that e.g. obsessing over D&D is not merely a hobby or interest, but a desire to escape from a life and self you hate.

I know a few people who obsessed over heroic fantasy (D&D, Dragonlance, Warcraft, etc.). None of them hated themselves, suffered much, or felt a great need to escape real life (except that when it was boring). They all grew out of it after a few years -- still play, but do not obsess any more.

I don't think your thesis is empirically correct.