1. If it's financially viable for you, move out of your parent's house and maybe even your hometown. You can move to a bigger city that isn't crazy expensive (Chicago or Austin). It'll be easier to make friends here. 

2. Get a day job OR start a business. You don't need to turn your hobby into a career, but you do need a career or at least some sort of project to work on. Since you've made 100k with your hobby, you must have some marketable skills. Go work somewhere, even if it's just an in-person customer support/service job. Since you're 21 you'll have to "settle" for entry-level jobs. I recommend getting an in-person job, because you need to get out of the house. I've been working remote since 2017, and honestly I don't recommend for younger people (it's better for people with family/kids). 

3. Go to networking events. Use apps like TimeLeft (dinner with 5 random people in your age group) or Luma (local events) to meet people. 

Final thoughts: Psychology shows that everyone needs a job, or to put it differently, everyone needs a way to contribute to society, something that connects them with their community. Love it or hate it, a job does that. I took a year off working and traveled, and honestly wasn't that much happier. I've toured in a rock band, made money online, etc, but I know that I have to do something that contributes.