I'm deeply jealous of my former classmate from elementary school

For years, I’ve been envious of a former classmate from elementary school. She’s a few months younger than me but looks older. She dresses stylishly, has a fit, toned body and a mature sense of style; she comes from a wealthy family with a big house and a farm. She’s blonde, athletic, has lots of friends, goes to festivals, etc.

What I envy most is that she’s into sports—specifically equestrian vaulting. She’s good at it and has a real passion for it. I don’t have anything like that. I’m interested in writing, but... I’m afraid of failing or that it’ll turn out badly, so I never actually start. How can I stop envying her? I constantly check her Instagram—her stories, her reposts, everything. Whenever she posts a photo, I look at it and compare myself to her. Or if it’s something from a competition, I admire how she manages to do it. I don’t usually compare myself to others, but this is different... Yet, I know she isn’t exactly the best person. Maybe she’s changed, but I remember her from elementary school excluding me from the group just because I wasn’t good at sports; she was mean to me—and to other classmates, too. I know the solution is probably to block her, but I just can’t bring myself to stop following her.

The reason I don't write is because I'm so scared to do it badly that I rather not do it all. But I know for a fact I will regret not writing my story.

I'm scared that I write my characters badly, that it's all dialogue since I don't like writing descriptions much.

Can someone give me some advice on how to stop envying her and actually do the stuff I want to do?