She’s given you pretty vague constructive criticism! It would be unfair for you to try and win her back based on her assumption that you’re living in the past. You might want to tell her how much you want to try and work things out, but you’d be grateful if she could elaborate on specific incidents of what she means by your living in the past. That’s really the only way you can even consider her complaints.
On the other hand, she may just be throwing out a blanket statement like she did about living in the past, because she isn’t interested in giving you specifics because she doesn’t really want to get back together.
So your job is to find out if she really does want to get back together, and if so, what particular things you do that make her think you’re living in the past.