Something similar had happened to me, don't give up. I was very apathetic in my teens/early twenties and it reflected (no social life, no social skills, ate like shit, didn't work out, etc...)

One I hit 23 I decided I needed to get my shit together and started to get into a rut very similar to what you're experiencing. I had one really bad 'fling,' where I got attached and thought she was too. She had told me she was in an open relationship, and since I was YDAFOC I believed her. This definitely cast a shadow mentally for me when trying to find relationships and made trusting anyone incredibly difficult. I hated attachment because I didn't want to get hurt.

At one point I was entirely ready to give up dating and let the cards fall where they may, but decided to give one last match on Tinder a try (she oddly reached out first which was unusual). Fast forward a few years we're happily married and couldn't be better. I knew pretty early on she was the one and that I could trust her. I was very forthcoming early on that I hadn't been in a long relationship before and she was very understanding. Dating can be rough for sure, but I definitely wouldn't advise on giving up if love and a true relationship is what you're after. It's hard work but it's worth it.