Dating my best friend and feeling less than.

29 year old male who's had a deep friendship with a girl for over a decade. Recently I've gotten sober and have started taking care of myself, and I've turned my friend into what most would consider a girlfriend. Only thing is, now it feels like she doesn't value me and only wants me around for validation. If I'm not doing something for her, she seems to not show interest. She's been talking to her exes, acting distant, and my gut is telling me something is wrong. This has brought me lots of anxiety and I'm aware I've let her behaviors play a role in my thinking which isn't good. I feel like I showed her my sensitive/insecure side and she's completely turned off now. It feels as though she was very hot in the beginning and now pushes me away when I try to initiate any intimacy. It truly hurts and makes me feel less than, like I'm not good enough which I know isn't true but I can't stop overthinking about what I'm doing wrong. It takes me out of the present moment and in turn, creates even more anxiety. Any recommendations on how to overcome this constant worry?