Persistance

Hello,

so me and my ex were together for a while until I decided to break up with her. I did it out of anger at that time, but later on I realized that I loved her way too much to let her go. She loved me a lot as well. I have tried to get back with her but she straight rejects me. Should I persist with her and do anything I can, or just give up?

No real details here so it's hard to say but I'm convinced now that badgering is counterproductive.

I'd briefly communicate your feelings for her and that you want to make things work and that she should contact you if she changes her mind. Then go no contact.

Without any details it's hard to know, but it seems like she's punishing you for breaking up with her.

Own it and say you acted rashly and you're sorry, but don't beg. If she doesn't want anything to do with you, say you understand and that this isn't what you wanted.

Then go NC and accept your loss

As someone who is a dumpee rather than a dumper, I say let her know your feelings then let her have her space. You're really going to need to prove yourself if she does want to give you a chance.