A new friend tells me that it’s much more difficult but much more rewarding to come up with your own quotes. Thus:

“I’m better than that. I’ve wasted so much time on someone and something that didn’t deserve it. It can’t run my life anymore because I won’t let it. There’s nothing I can do but let go. So, I’m going to do just that.” -Me

Repeat as often as necessary until you regain your self-confidence.