Asked my crush to be roommates he responded with “yes”. Could this mean he's crushing back?

It may mean he wants a roommate . Ask him directly if he is romantically interested in you.

I really hope so for your sake. It is promising so hang in there. If he really didn’t want to be around you he would have said no so he is open to possibilities.

Well you can ask his relationship status as part of the "feeling out your cohabitation" ploy