Hi, and welcome!
I was terrified of joining a forum at first because I've had a lot of negative experiences with being online, and interacting with groups of people irl. But my experience on here has been very positive. Hopefully you'll find it friendly here too!
My family (not so much my parents but my extended family) strongly encouraged me to go the route of completing a college degree in four years, and work in an office or get some form of a white-collar job.
Well, that is not me in the slightest. I struggled through college for several years and now I'm "taking a break." I would go back if I found a school that was the right fit (which would probably be an online school since I always seem to get bullied when going to school in person).
And as for the job? I tried almost everything lol, but nothing in the realm of what my family suggested. Now I make money casually working with other people's dogs (training, walking, grooming, etc).
It is totally okay to not have an office job, or the kind of job people pushed you to have. You're your own person, and what works for someone else probably won't always work for you.
I completely understand and empathize with not being able to leave the house. People can be terrifying to be around. I had to work myself back up to leaving the house after my last really bad mental health episode a few years ago. It's still hard.
I'm glad you've found that going to the gym and eating healthy helps you! I'm not a gym person because I'm disabled now and I don't have the physical strength or stamina to do much more than go for walks, but I was very athletic when I was younger and I miss it. I think there are other people on here who go to the gym and work out who would probably be happy to talk about working out with you!
As far as getting a "proper" diagnosis... you've already been given really good advice, and I'll add that it can be difficult to find a good psychiatrist. You should research several in your area and see which one sounds like the best fit... or meet some in person if that's possible.
Lastly, you said you live in a small town but don't like being outside because of people, is there anywhere you can go that's totally private? Like a forest, or a nature reserve? We have a lot of those near where I live and since I live in a more densely populated area, it's good to get away to the parts of town that are more natural and less populated.
And do you have any pets, or do you like animals at all? I know I ask everyone that lol but animals are much better companions than (most) people imo. I've found it much easier to rely on my dogs than other humans, for companionship but also physical and emotional wellbeing.
I went on for way too long as always, so sorry about that... Hope you enjoy it here and don't be afraid to ask for advice!!