Does it sound like an anxiety disroder or depression? or both?

I'm only 17 years old. My father passed away when i was 13, and my mother passed away just 6 months ago along with my stepdad. My father was very Ill... My mother & stepdad died in a motorcycle crash. He died instantly... While I had to watch my mother suffer everyday in a coma for an entire month...I feel like i can still see her suffering in my mind... I feel like I should've kept her on the feeding tubes longer... I feel like I killed her... Even though every doctor and nuerologist said it was for the best because she would be in a vegitative state... I know she wouldnt have wanted to live her life that way. I find myself thinking life is pointless for me now, I dread on what i could have done, said, etc differently, and find excuses to blame myself for almost everything. I have not been to a doctor yet. I feel like nothing really matters any more to me. I used to be the head varsity cheerleader, always out and having fun...and now it seems like when Im out, I'm jealous of everyone and I feel like my life can never be like theirs again, but when Im alone its like im staring into a mirror and I no longer know the person staring back. I want to find ways to cope with everything. But, i dont know how. I find myself thinking sucicidally daily, never completely serious, I don't have the balls to do that. But, if I did it would have been done by now. I hate myself for everything thats happened, and I feel like no one wants to talk to me about it. I hate the life I live. I get nurvous now, that never happened before. Like, if i hear people laughing I automatically assume its about me. I get heart palpatations when nothing seems to cause it. I get lumps in my throat. I feel the constant need for reassurance. I hate that I always think of the worst possible situations. If an ambulance passes me, i automatically pick up the phone to call my brother and make sure he's okay. I hate that everything I do I can never feel calm about. I feel constantly shaken up. I can't sleep at night, and I hate being by myself because it gives me too much time to think. More often than not I take nyquil to sleep and stop thinking . I hate what my life has become . I envy who I used to be before this all happened. Whats wrong with me...?