Hello! I am new here. I am a 17 year old girl, and I just want to know..

For quite a while I have been feeling terrible. My heart has been pounding, for some reason I'm shaking a lot, sometimes I feel as if I can't breathe properly, I'm dizzy and lightheaded. I'm afraid of many things, such as what I dress in, even though two years ago I was filled with confidence and couldn't give a crap. I feel like if I died it really wouldn't matter, and I think about different ways I could kill myself, but right now I don't think I could act on it. Because I'm also afraid of death. The future terrifies me, but just a year ago I was burning with passion for what I wanted to be, who I wanted to be and basically just the future. I can't relax, only forget about my problems for a little while when I watch movies, series or read books. Anything that stops me from thinking really, but it has lead to me burying myself in fiction. I come up with bad excuses a day or a couple hours before events so I won't have to attend them, even though I really wanted to go for a long time. And I've lost interest in almost everything. School, family, friends, future, myself.. I cry myself to sleep, I cry when I'm alone and no one can see me.

When I'm at school I cover myself in a facade with smiles, laughter and spend all my energy on that as well as listening to my friends problems and comforting them. I would do so much to see them happy. When I come home I'm exhausted. That's why I don't spend time with friends outside of school, I simply don't have the energy to hold up the facade for so long. I even pretend everything is okay when I'm at home, my parents have no idea. I think, because they don't seem concerned about me. Lately I've been skipping school and I feel awful because of it. At first, my friends were really worried and asked why I was away, and I told them I was sick. But then they stopped believing that I was sick, I ran out of excuses, and they stopped asking. I think they're angry I'm not in school every day, but I feel like I physically can't go to school. This makes me sad, angry with myself and even more frightening to go to school.

I haven't talked to anyone about this, which makes me sad. The thought of telling anyone freaks me out, because I'm afraid they wont' believe me and think it's just another excuse. The reason I started to think I have anxiety or something is that a friend of mine is struggling with it, and I read something about it on tumblr that described scarily well how I felt on a daily basis. And I know reading about symptoms online can freak me out even more, and maybe enlarge the problem, but I just want to know. And I want to share my thoughts with my friends, but as I said I'm afraid they're going to laugh in my face, and I'm not even sure what it is! And I'm scared! I have asked if I can talk to the school nurse though.

Can anyone give any thoughts please? I'm sort of freaking out publishing this!