i promised her i would never give up on us, even when she did.
don't let that stop you from getting over her and her out of your life. While you were together you never did give up on "us." It's her that has given up on the two of you.
Have you ever heard the saying: "No sense flogging a dead horse?" It applies in your situation.
You've been flogging a dead horse and it's causing you anxiety, grief, being unmotivated in your own recovery and healing. Counceling will help you to see that. Start before counceling to help yourself in your healing by accepting that you should stop this never giving up. That you should indeed give up because it takes two people to form a relationship not just one (you).
It's beyond being unhealthy at this point to keep on trying to be with someone who doesn't respect herself never mind you.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion