I never recovered from a breakup that happened 8 years ago
Did you hang out with anyone after that?
No, I've never dated anyone else since that breakup
It's okay to be sad after breaking up, but you shouldn't dwell on it forever.  You should be ready to move on with your life, either with friends or with a new love.
I don't think I'd be ready to let go, I still think about her all of the time and wonder what happened.
8 years is a very long time to dwell on a relationship. I don't see any positives from you continuing to hold on like that. I want you to start dating someone, even if you are not really interested in them and you just casually hang out, I think you need to learn that there are plenty of great options out there for you.