Hi Sarah,
If I may lend my thoughts…for several years I have been obsessed with a few women much as yourself. Whether they were the woman I was left for or someone who seemed to have everything figured out. I just never seemed to measure up in my eyes and I was so very deeply affected by it. I was ashamed of my obsession.
I got really tired of feeling this way and decided to confront the issue head on and disect my feelings layer by layer. After a lot of self examination I realized that I can choose how I channel that obsession and honour the specific things that I admired about the person, I would then model those qualities in myself to embody those things in my own way. I would take fashion tips and make them my own and explore the ways I too can be as successful etc.
Now when that feeling comes up again, I am able to acknowledge and use what I was previously jealous about to improve on myself, the initial self hate still appears at first but it goes quickly as my consciousness makes the shift.
Hope this helps, it takes a bit of practice.
Deena