Mental health???

Okay so i would never never try to self diagnose, im still pretty young (im 16) and basically i just feel like something isnt right? I act out and push people away and i over react and get really nasty but im not generally a nasty person, and then sometimes i can be really happy but seconds later i will be shouting horrible things at people and snapping and then again a few seconds later ill feel guilty and apologise a billion tims. and i have felt absolutely horrific for quite a while (sad, extremely suicidal, killing myself is literally on my mind 24/7) im constantly paranoid that people are lying to me, trying to trick me, etc etc, im intimidated of pretty much everyone, even my best friends scare me (for absolutely no reason) and sometimes i even feel like people can read my mind and i just generally feel like im going crazy. I want to speak to a doctor about this but im terrified of going by myself or making an appointment or just doing something wrong, but i absolutely cannot bring any of this up to my parents because they act like im putting it on (i get frequent panic attacks and my father literally sat with me while i had a panic attack in hospital and still thinks im faking them) and i know that my mother will just try saying its because of my eating habits or my sleeping pattern or im being lazy so it effects my mood etc etc.
Honestly, i dont know why im saying all of this, i just want to stop feeling like.. A prisoner... (Also In my own mind...) I guess?