GO SEE A PSYCHIATRIST
is my first advice.
I have a rule of thumb that anyone who has so much enough contact with reality to say "I feel paranoid" is not actually gone into the pure psychotic state that the thoughts can be called Paranoid. In my experience only chronically psychotic people have had that experience to recognise their paranoia
and state so...not a 18 year old (I guess you have not been chronically psychotic, right?)
Your symptoms are suggestive of severe depression
and hence my advice is again GO CONSULT A PSYCHIATRIST