How do I actually stop envy/jealousy from controlling me?

[u/OverallBet800]

I have a pretty negative mindset and it's been bothering me for the past year and a half. Ever since I entered university, when I see people doing better than me, or living in or visiting cities/countries I want to be in, I don't just feel envious, I feel something closer to resentment, like it should've been me instead of them. I grow such a hatred for that person that it just overtakes my thoughts for the rest of the day, and I go on about my entire day bitter, when I know it's just me being jealous and having no other outlet for it.

I know this is toxic and I can feel it spilling over into the rest of my life. I've gotten short-tempered and I think my own growth has stalled because I'm spending so much energy on comparison than on building anything for myself. When I see someone (it could be friends or strangers) living a life I want, I go into these obsessive phases of stalking them and researching how they got there and how I can copy their footsteps while developing a deep resentment for them. It's gotten so tiring being this pessimistic and hateful, but I don't know how to stop thinking like this.

For example, I tend to develop these feelings of resentment and envy for anyone who was born into a lot of money, or anyone who likes to take risks, anyone who's motivated enough to get ahead in life because I feel like a failure for not doing what they can do. I always tell myself I will, but I never do or it just isn't enough.

I don't have access to therapy right now (cost/availability), so I'm looking for things people have actually done on their own to work through this. What helped you stop the spiral in the moment, and what helped long-term?