What Is The Cause Of Sadness?

Can I tell you some symptoms and you tell me what I have? I am not really sure what I have but I think its urgent. I often feel sad inside, and I cry a lot when something in a story happens because i feel the same way. And they are normally sad ones. I think thats unusual because i normally never cry, I keep it all inside. Its kind of hard to tell you what Im feeling, but Im trying. I feel sick a lot, I shake uncontrollably when Im nervous and my breathing gets kinda faster. If I stand up too fast, I get really light headed and sometimes I fall over. I cannot sleep very well and i get tires easily. I have horrible self confidence and i also have troubles with trust. I also used to cut, but I am now 7 days clean.