Help? Moodswings, easily angered.. etc! (Easy 10 pnts)?

From day to day life I always have mood swings and I get mad so easily it's unbelieveable. Sometimes I will think I am having the best day of my life and then bam, it's the worst and I just want to kill myself? Are these mood swings normal? They get triggered by the smallest things and sometimes nothing? I also get very easily disturbed, saddened, and/or mad. I sometimes cry over stupid things. I use to actually cut myself a year back or two ago to deal with these emotions and that really helped but now it's overwhelming and I don't want to start that again? So what is wrong with me and why do I get to sad, mad, or whatever so easily? And what's up with all these moodswings?