Hi, I'd like to help you with your question.
It sounds like your relationship with Angela has been a back and forth situation and it still hasn't gotten any better.
Although you have strong feelings for Angela, she has not been forthcoming about her feelings for you. From what you said, it sounds like Angela has seen your relationship with her as a backdrop in her life. When things don't go well for her, she comes to you. When things are fine for her, she backs off your relationship. As a result, you are left wondering if you have a relationship at all.
It comes down to deciding how you want this relationship to work. Do you want to continue with her and allow the relationship to go back and forth? Or do you want to end it and move on? The healthier choice is to move on, but only you can decide that for yourself. Either way you chose, you may want to seek counseling to help you cope with the feelings you are having from this relationship.
I hope this has helped you,Kate