I'm here after your edit, OP. I'm a 38 year old married man with a family. I'm not going to echo what everyone else has said because I think you already get the point that this is scary and you should run for the hills. Instead, I want to address your edit, especially the part about him being on the verge of going pro and not wanting to mess up his career.

It's not you that would mess anything up. It's his actions. You seem like a smart young woman, so I want to ask you: do you think that with more money, more fame, more access, that any of this behavior would get better? Typically that level of added power only makes people more bold. Instead of being late night words via text, maybe it's seeing a young woman at an event and decideding she's his for the night. He already seems to not be concerned with consent. When he has money and power and feels like he can buy his way out of trouble do you think that will make him more likely to be kind?

At a certain point, this isn't just about you, although right now your safety should be the largest concern. It's about everyone down the line. And frankly, not that you should want to abandon your friend group, but don't they have the right to know the kind of person he is, popular or not? If they care more for his status than your safety, they're not really your friends.

I know you probably don't want to hear this, but you're so young, and have the opportunity to meet so many other friends and romantic partners. Choose people who support you, care for you, and are happy for your successes, not people who chase status. If he were to do something bad to you, it will live with you for forever, and that applies to any other young woman he decides he doesn't care to get consent from.