My ex and I are best friends… ?

I broke up with my girlfriend because of religion. We’re both girls, I’m religious and at that moment I felt bad everyday because I felt like a sinner. I explained everything to her and she was very understanding. In this period of 5 months I also started to lose feelings and by the time we broke up, I was over it. We decided to stay friends because we were already best friends before getting together… Now 4 months have passed since our break-up and I have a crush on another girl lets call her Amy from work. She’s straight so there’s no chance we’ll ever be a thing but my ex still gets jealous. I have told her that me and Amy are just friends but she tells me I have to choose between Her or Amy. I don’t want to lose my best friend but I also want to stay friends with the people I want. She made rules that I have to follow like: you can’t text Amy, you can’t meet up with her, you can’t make photos of her, etc. Now she also makes a problem of my other collegues. She told me that I can’t meet with them or give them too much attention until she feels better about our break up. I just don’t understand why I should have to choose between people to stay friends with her. She also made me promise that if I ever want to be together with girls again, I have to choose her even if I don’t like her. And if I date another girl, she will ruin my life. What should I do? I really don’t want to hurt her again, also because I am her only friend…
My ex and I are best friends… ?
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