Why don't I feel normal? Please can I have some serious answers?

I head seems so messed up. I haven't cut myself in a little less than a year but when I did cut myself I felt so happy. It hurt to cut myself, but once it was done I felt so good. Like a whole lot of weight was lifted off my shoulders. I have really vivid dreams of me killing people or people dieing. There are times where I try to save them from the enemy. I feel so depressed at times which has sometimes led to an anxiety attack. I am a patient person and always have a smile on my face. For as far back as 5th grade, I have bottled up my emotions. When I am angry I am full of rage and feel like I am on the brink of snapping and losing it. I cannot even remember the last time I cried.I workout out and run 6 days a week. I am a healthy 23 year old 5'10 1/2" and 180lbs. Sometimes I get so depressed I do not even want to eat. When I close my eyes I feel the emotional pain.I no longer sleep because I have this pain in my shoulder and neck and sometimes lower pack to the point where I cannot sleep. What is weird is the pain will one day be on my right side and then the next be on my left side and both in the same spot. The pain is not from working out because I do it with perfect form. Maybe this is where I store my stress, I don't know. Deep down inside I feel so empty and lifeless. I have NEVER had suicidal thoughts. So when I did go to cut myself, everything just seemed like it stopped and slowed down a bit. It felt great but I knew it wasn't good for me.Then again things do seem to go at a faster pace then they should be. What the hell is wrong with me?