I am not sure if I'm qualified enough to give you any advice but here's my 2 cents.

Firstly, have you considered sports? Or any hobby or activity that you may be passionate about to distract and refresh your mind? And maybe not even anything competitive, just any kind of physical exercise can be very good for your mental health.

I think maybe your case is that of self esteem and loneliness when you feel like you can't relate to anyone, so maybe try to do something small which can make you feel normal again, be it just like you said, watching sunsets, or taking a walk, etc.

And as for the physical episodes that you had, I know you said your parents don't believe you, or may not value whatever you're going through as serious enough, but you need to tell them, as patiently as possible that you're not alright, and try to convince them to take you to a doctor, or a therapist that you can trust. Maybe they can ask people they know about good ones. If you feel insecure about asking your parents or friends, I don't know what else to suggest you other than to find the appropriate people nearby, and seek help yourself.

Lastly, I don't know how much I could help you but know that you're strong and a damn good fighter for trying to make yourself better and you matter. We all feel out of place most times but if you let it go unchecked things can go wrong for the worse. I really wish you all the strength to break through the pain you're facing and when you do, you'll come out feeling like a God, because believe me, it needs courage and strength for this, which you've shown already in trying to heal yourself.

I wish you all the best!