In my opinion, there are two things that are personal motivation and surrounding.
I'll tell you about my experience. I was crazy about getting into acting. I've been dreaming about the scene since I was young, and everyone said the theater was mine. But before I went to acting class, the master told me that I could use 20 pounds in a month. I'd give up and say it's impossible, but every morning I got up at 5:00, I ran, changed my food habits, I gave up all the nasty stuff. In the end, I didn't get in (because I didn't even go to the exam), I dropped 15 kilos in two months and felt really good. Changed because the theater was my main goal at the time. It's about motivation.
If you want to change, change your environment first. It means a lot, actually. You want to be an athlete? Then go to the gym, get yourself new acquaintances who support the idea of sports, go to various master classes, charity races and stuff. And then everything will be fine.
I hope you can make it.
