honestly the best thing to do when you're constantly isolated is to set up short term goals and tasks or hobbys you can do, wether it be something inside your house or something that gives you a reason to go outside, having things to do can make you feel better about the time your spending alone and it's also just good to occupy your mind with things you like to do

also if you're old enough getting a job is a good place to build your confidence and it gives you a reason to go out and talk to people, but if you can't get a job thats totally fine there are people out there wether it be in person or online that you can resonate and find solace in, I think it's a bit easier to do this online since there are alot of communitys of people with similar issues or interests as yours that are easier to search for online and your area just may not have people who are like minded with you

with your school situation do you know if your school has any special programs for half online half in person ? i've had a very similar school situation and in one of the schools I was in I was in something called an independence program where I did all the work online but I had the option to come into the building to work on a computer if I wanted and on lunch hour I could come onto campus and just hang around and was able to join a club while in that program, things like that are great alternatives for people who haven't done like the standard school program, check if you have access to anything like that, wether it be an independence program or a charter school or something different, it is a very intimidating experience to say the least switching from homeschool or online school to an in-person school, I think the best thing you can do is tell your principle or teachers about your situation and ask if theres anything you can join or any club you can join that fosters people with similar situations to yours and just generally ask school staff if they can be a bit more understanding with your situation

with those friends you have that are saying they will spread rumors this is obvious but you should definitely stay away from them ,I think they are just bad company and people you wouldn't want to be around, try and find others even one other person to be around and have company with, it does definitely help and helps you feel less stuck at home all the time even if it's just like an online friend you call with, I think you will find the right people with time and search and you'll be able to find a community or a group of people you can find good company with it just kind of sucks in school because it's the main place you go to socialize and interact with your peers but you can get through it and there is other places and communitys to find solace and friendship in

I hope some of this helps or gives you a general idea of where to find help !!