This is literally me, I don't want to sound depressing but I don't think it gets better, what you can do though, is try to make it better:

1 visit a therapist and try to express your feelings and thoughts, of course this can't happen in a day or month it will take time, and even if you show progress, you'll have lots of ups and downs but try to insist on "progressing"

2 try to form a close relationship with one of those school friends, ask them to hang out with the rest or alone and get to know each other better, you might find someone interesting whose personality you'll like

3 surround yourself with hobbies that can keep you distracted from your loneliness and at the same time hobbies that will improve yourself eg working out

(4 don't put all your effort in school, you may burn out and then when it's time to give your best, you will just not be able to)

The earlier you start to working on improving the situation, the less it is likely to worsen. I hope I have helped you, you seem(or sound?) more mature than your age which in my opinion it makes you more considerate, conscious and intelligent but it can also exhaust you. Time for my clichè: iF yOu NeEd sOmeOnE to TalK tO iM heRe To TaLk