Ultimately, only you can answer your questions. As someone who over 10 years ago began a weekly FWB relationship with a neighbor, I can tell you that after having sex with someone for an extended period of time you can't keep that up without developing feelings and bonding. (We've never lived together; he has been with a long-time partner for almost 40 years but without intimacy for at least the last 20. Ultimately, I moved away but we still remain close friends.)
You do, however, mention that hooking up with your roommate is "against" your better judgement (and I expect for good reasons.) That to me, is most telling. You may get "release" from the arrangement, but I don't have any sense that you truly enjoy it. Perhaps you feel used? Might your roommate have developed feelings for you--hence being prepared for sex--and unable to tell you he's into you? Or could the sex be one way the roommate sees as paying you back for helping him out in this time of Covid? Do you see the roommate as a long-term partner?
I don't see how you can resolve your own feelings without having an open and honest conversation with him. And it will take more than one conversation. Just be calm, clear, non-judgemental, no accusations, and don't let the conversation veer off onto tangents. You're not criticizing here, you are merely seeking clarity. "What are we doing? Where is this going"" And he must be a decent guy, or you wouldn't have asked him to move in with you. If he's a satisfactory roommate in all other areas--sharing chores, being companionable without demanding special treatment, etc.--then he is likely to be honest in communicating and navigating this situation with you.
Hope this makes sense.