I(22 M) and my girlfriend(26F) have been dating for a year and 5 months, I won't say the relationship has been all bad it had its good times and good moments, but recently we been having a lot of arguments, one of the things that made me really mad is how she will compare me to her exes in various ways, saying I wasn't much of a gentleman even though I cook , clean, take her to work and always try my best, overtime this feeling kept making me feel worse, also I had problems with premature ejaculation so want night while we were having sex and she was drunk I came fast and she said not to blame her if she slept with someone else, even tho she said that she only said this stuff in the moment because she was drunk I have always been worry, she will never admit her wrongs, about two months ago I told her how I felt, about two months ago I brokeup with her because I couldn't deal witht the arguments and comparisons, after I gave her this chance she has actually been better hasn't argue or anything but I have been mentally checkout even tho I gave her a chance, 2 days ago I once again brokeup with her after an argument, she ask me to not breakup with her that she sees a future with me, after awhile I accepted and we have sex which now I am regretting, in all honesty I love her too but being with her is not causing me happiness, also she always once to go out and I have yet to finish my career I been spening a ton of money, I know we are at different stages of life, I don't know what to do I don't want to hurt her but don't want to be in a relationship with her anymore what should I do?

TL;DR: I don't know what to do in this situation I don't how to end it after giving her hope and having sex with her.