Jealousy is an emotion like anything, it's tough, unavoidable, and a build up of energy. What matters is what you do with that energy. It always seems like a lot of advice boils down to "ignore/avoid" or "use it to fuel yourself/get angry/git gud"- I always got this advice and it never helped me.
Honestly what has always helped me to deal with jealousy is to lean into it and look straight at it. What is making me jealous about this person? What do I feel is lacking in me that is making me feel this way? What can this emotion tell me about myself and my own needs and wants and how they aren't being addressed? It's not that other person making me jealous, it's something internal. That's one thing to note, to not blame someone outside yourself and realize that other people really have no power over you.
The other thing that has always helped me is turning that negative energy into something positive. I compliment and am kind, even when I feel jealous. Especially then. I treat those people like fully rounded other humans, with their own highs and lows, faults and wins, and not objects. I practice being kind about the content, even internally, and say nice things instead of repeating self-negative internal talk in these instances. I do draw fanart. Actively practicing positive actions can help transform those negative or jealous emotions into positive ones, through practice and repetition. Don't continue those negative thinking cycles- replace them with something positive.
I think you're almost there, OP, you just get hung up on giving attentions to the object of your jealousy in the hopes that it will reflect back on you (ie: I copy this style to get what they have, I give them attention so they'll give me some) when it's really about soothing yourself, not an expectation of reciprocation. Try to give kindness without expectations and see where that gets you. Also, cast a wider net. There's a problem with copying someone's style completely and intentionally, but to create your own style is to take ALL the things you enjoy and incorporate bits and pieces from each style or way of working that you love, into what will be new and yours.
You're already the best you, and nobody else can have the same voice that you do or the same style, as no one else has the perspective on the world that you do. Don't squash that by trying to mold yourself into someone else. And rest assured that feeling jealous or not good enough is not some reflection of reality or that you are broken in some way: every artist struggles with these things. It just means you're human, it's a feature not a bug
So don't hyperfocus on these feelings meaning something wrong with you or lacking. They will come and go, no matter what you do or how good you get.
Very best of luck!! I hope you can push through this rough patch and start feeling better!!