First relationship (online), feel like I'm being used but scared to leave

Hey, I need some perspective from people who get it.

I'm closeted—nobody in my real life knows I'm gay. I've been in an online relationship with a guy for [however long] and he's literally the only person who knows this part of me.

The problem is the relationship is really one-sided. I send him content, hours of videos of me talking, I buy him stuff, I'm always the one initiating conversations. He gets drunk often and I spend hours comforting him while he cries, and then he doesn't even remember the next day. When I bring up that I'm putting in way more effort, he gets defensive or dismissive.

I know I should leave. I'd actually feel relieved if it ended. But he's the only person I can be myself with, and the thought of going back to having no one who knows me is scary.

Has anyone been through something similar? How did you leave a first relationship when you were still closeted? How did you find support after?

Any advice appreciated.