Honesty is the best policy. You already made it clear that it wouldn’t kill you if things petered out (as they have been doing). So if you are honest, and she bolts, it likely wouldn’t be the end of the world. However, if you want to salvage some sort of relationship, then outline your issues in a polite but direct way. Say something like “We used to enjoy hanging out together, but things have changed. One thing that bothers me is that it seems like you want me to drop everything when you want to hang out, which is frustrating. I do like hanging out with you, and would like to continue to do that, but from my perspective, things need to change.”