My (20M) gf (19F) said “she should’ve given the love she wasted on me to her ex instead” while having an argument. Now I feel like leaving but she’s begging?

We had an argument the other day due to me not being able to read her signs that she needed babying(I'm really really bad at picking hints. Like i can't get even the most obvious ones) , which led to her telling me loving me was a waste she should've just given that love to her ex instead. This isn't her first time saying other guys in her life are better than me. Now she's been begging since yesterday for me to give her one last chance. I'm tired of giving her chances. But the thing is she's the sweetest person when she's not mad so I'm having second thoughts whether to leave or not.

Edit- i can't see any comments other than the automod's. So please excuse me not replying to your comments. I can only read them through notifications.

Edit 2- After reading all your comments (from notifs due to reddit glitch) I've decided to leave her. Thanks to everyone for helping me out