Codependency Support Group
Codependency is defined as someone who exhibits too much, and often inappropriate, caring for another person's struggles. A codependent person may try to change, or feel shame about their most private thoughts and feelings if they conflict with the other person's struggles. If you are on a journey towards self-love, this support group is for you. Join us and find others...
I'm just wondering if like me do you have a hard time telling her how you feel? If it is as you say, the friendship/romance on off thing, then why don't you tell her how you feel. What do you have to loose? It would be far better than torturing yourself every weekend. If she has moved on, or isn't interested in a relationship with you, then maybe you need to move on? The situation just isn't healthy for you.
This is a serious issue and you do need professional help. If you can't be around her daughter without getting obsessed over her, you need to step away - her daughter is a trigger. Just because you want something doesn't necessarily mean it is good for you.
best wishes, earthlake