Hi,
Sounds like you're having a pretty tough time at the moment and I can really sympathise with that, being at the end of my drama-filled secondary school/sixth form years.
I'd like to ask first of all why you felt it was necessary to create this new personality for yourself? This seems to be the root of your issue. You say you are an extroverted person so why not start being more yourself around school? I have no idea how old you are/the situation at your school and I know it can be very cliquey. But if you feel comfortable, try to branch out and speak to new people e.g. people you sit next to in lessons, people in your form group, people at clubs or friends of friends. This could be a way to make new friends who see you as the person that you are.
If you feel that's not going to work, maybe try to slowly start being more yourself around your current friends and see how they react. You shouldn't need to create a whole personality, especially around people you consider your friends. Maybe you could even have a chat with the friend you actually like and tell them how you're feeling and see how that goes. If they really are a nice person then they should want to help you.
If you don't feel like either of those options would work, I would not advise telling your friends that you don't want to see them outside of school, unless you feel you can be honest and tell them how socially drained you're feeling. If you don't give them a reason that you don't like hanging out with them, they might take it the wrong way and you definitely don't want to hurt their feelings.
I really hope this helps, ask any questions you want abt school/friendships etc, and keep me updated!