My ex is trying to pretend we never happened

So my ex, L, and I were together for a long time, off and on. While we were together, she found out she didn’t have feelings for me and kept trying to break things off, but admittedly, I kept begging her to stay, until a month later when she left for good. I saw that she was dating someone else, and in my anger accused her of emotional cheating and that she had cheated on me while we were together, but I was just angry, but I made myself believe that was true. After getting the full truth from a mutual friend, it was. Full slap in the face, and I realized how bad I treated her. I tried to stay away, but I had to message her because I still had feelings for her. She was nice in replying, but said she was still dating the same guy, C. I’ve never liked C. He’s racist, sexist, hangs out with bad people, and I just knew would make her life worse. So I did something awful. I tried to convince him she was sleeping with me so he would leave her. But he didn’t even look at the message and blocked me. Fast forward, and I keep missing her. I’ll look through photos of us, videos, and I just can’t move on. It’s been over 3 years, but I’m still holding out hope. My issue is she’s moved on completely. We had so much love, we still have love. I know we do, but she doesn’t acknowledge anything! My ex’s kept leaving because they found out I still love her. I don’t know what to do anymore

At the risk of sounding harsh, you definitely do need a slap in the face. 3 years and you are still pining for someone who quite clearly doesn't want you? If ever he did leave her and she came back to you, you would always feel 2nd best. That is one of the worst things in the world to be! Move on! Maybe try and focus on something other than a relationship? Because it isn't fair on other people you are dating if you still have feelings for your ex. She has most definitely moved on and you need to do the same. You don't sound ready for a relationship so try and find something else to do/focus on.

("you definitely do need a slap in the face." Can I have one next? And - how much? :D) Pigeon, I agree with every single thing NiceHeart's just said. You need a project. Also - On-Off is a massive indication that the relationship is past it's Use-By already (was meant to be a stepping-stone and practise-run, not a destination) and that the rescucitation attempts aren't enough to revive it to where it can get up and off the floor. As you now see. 'This parrot is deceased!' (- Monte Python). While you're there, pining, instead of burying and grieving over, you're putting in jeopardy your next, much better romance, possibly "The One", by ruining the timing synchronisation. The sooner you start crying, ranting and grieving it out, the better, therefore. On the other hand, it HAS only been a month or so, combined with the fact it was a long relationship (many habits to get out of and empty holes yet to become re-filled), so....I wouldn't worry or whittle about it because you're probably still in Shock & Disbelief at this fresh point.

You have to get over her. If not you're gonna make yourself miserable. Even though you still have feelings, she's totally moved on. I know you have your regrets, but make it up by finding someone new and give them the love that you wanted to show her. That's all you can really do.