Need help from someone with psychology background. I really think my friend is a sociopath and need to know.?

It is impossible to diagnose someone from a 3rd party observation of that person's behavior, particularly when that third party is involved in an emotional relationship with the person in question, however, you might want to check Borderline Personality Disorder. The clinginess followed by rejection, anger outbursts, need to be in every aspect of your life, unstable friendships (no frends to too many friends to breaking off friendships) - this is just my opinion here, but it sounds a lot more like a borderline.