I feel tied to my girlfriend.

I have a pretty big problem.
I am 13 and male. it all started with me having a girlfriend. Let's call her B. Me and B meet and have a decent relationship for a time. It was my first, and I was very happy. I gave it my 100% and for the first time I felt like I was loving someone the way I wanted to and I was receiving it in turn. However, this was likely my idealisation. I was young and naive. We met online and we did long distance. B was 12 and a bit at the time. However, after summer of 2023 our relationship gradually got more rocky. After a failed meet up in London she started to grow noticeably more withdrawn. She responded less. She didn't reach out as much to initiate. Eventually, she said she wanted time to think separate from me and that she's found someone in her country she thinks she likes. I'm understanding so I agreed. But still felt sad, but decided to keep it to myself. One day, I receive a text. She says "we're still friends right?" I say yes. And from there we had a relatively decent normal relationship. Fast forward to recently now, ill admit, it was on one of these days we mutually flirted quite a bit. Eventually she asks if we are really together again. Blinded by my emotions I agree. But almost immediately a few days later I realise my mistake. She isn't very good for me. I dont feel happy with her and I feel like its a chore to talk to her. Both before and after our quote on quote reconciliation, I've been joining matchmaking discord servers hoping to find someone to have a relationship with. Of course I had the foresight to not get groomed. I only seeked people my age. But every time, it was hopeless. Someone talks to me, we speak for a few hours at best. Basically never again. It never came to fruition. It was hopeless. Now, I dont know how to feel about the fact I feel like I'm cheating on a partner that I dont even really love and feel tied to. I dont know how to manage my needs and hers. Because I'm scared that she'll grow more depressive and upset than she already was during and before our initial relationship because of this. I've considered just telling her my parents found out about us and they don't want it to continue, thus breaking ties with her without her knowing anything. But deep down in my heart I feel like its wrong and that she deserves the whole truth. I'm in too deep now.