How do I deal with envy?

How to rid myself of this feeling? It makes me feel like a not so good person. Is therapy the ONLY way? I’m really struggling ever since I attended a 4th of July party at my partner’s house and seeing her interact with her family just made me so unexpectedly bitter and jealous. At one point one of the firework sparks hit her leg because she was standing too close and when she was hurt by it her mom immediately went to check on her which is something that definitely would not have happened to me.

I hate the way I can’t be anywhere without simply enjoying the moment or feeling happy for anybody else. Sometimes I get random urges to be cruel or say something horrible just so she can ask me what’s wrong or what’s going on and show care, I have no idea how to stop.

I tried therapy on and off but always switched therapists because the moment too much was said or I looked vulnerable to them I bailed. I also just despise the idea of anyone having authority over me which makes building yhat trustful relationship difficult.

I wish I could at least feel happiness for others even if I can’t feel it myself.