i think i am depressed but don't know how to confront it?

I'd like to start off saying; don't judge me. help me. background: im 17 male. my family has never been close to perfect nor do i expect it to be but when i or other members of my family fight, it eats me apart. I feel like my childhood was taken away and filled with bad memories. My most vivid memories is my parents fighting. I feel like if i told my parents they would treat me differently and i want nothing to do with that I don't talk to my parents or anyone else about it i know because i trust nobody. I can't afford to trust people because every time i do, it screws me over. I used to enjoy a lot of things but it seems like now nothing is of interest. family, friends, everything have 0 meaning to me. It seems like i have no purpose and i have no reason to live. I have thought about death, quite a few times. I haven't gone through with it because i feel like i would tear apart everyone's heart if did. The guilt of it stops me, nothing else. The only times i can think of happinesss or excitement is Christmas or theme parks. Neither phase me anymore. I never have energy and never feel like doing anything. I get angry easily and i have hurt people and regretted it. . (this is where the do not judge part comes in). I became a fan of marijuana because it masks my depression and i feel no negetive emotions. That effect only lasts for about 2 hours and i can't be high all my life. I've come to the realization that i need help but don't know how.