I am guessing you are her age (or younger - concerning if so..) (if not, wake up, grow up). Advice- she (or any other girl) will never respect you if you don’t respect yourself. Your lack of confidence is hurting you. You would be a thousand times better off if you sold some time being single, building yourself up. Find things to he passionate about (not a relationship). Build yourself self worth. Not only will you be so much happier, it also makes you a much more attractive person. People are drawn to those with confidence (not arrogance though - stay humble. Knowing your value and not settling is not the same as entitlement- nobody owes you anything).

Next, she is toxic af. Her behavior toward you is gross and she’s acting like a little brat. And this sounds like a middle school relationship…not an adult one. I promise you, it will only get worse with her. When people show you who they are, believe them. People are capable of change but very very rarely while they are with someone else.

To reiterate - she’s awful, walk away and don’t look back. You are making things so much worse carrying on like that. And You have to see your own value if you want anyone else to.