Let's not start out by sugar coating this, okay. You broke into someone's home at gunpoint because he stole drugs from you. That is almost the definition of a "bad guy" and "violent". Believe it or not, most people would not point a gun at another human being for any reason. You don't get to judge your victim.
Were there children ANYWHERE in the home at the time of the invasion?
Okay... as to the charge. You may have a shot, but will need to contact the ACLU (UCLA is a university in California and they don't care about your case) if you cannot afford your own attorney.
You won't be able to plead the case again... that ship has sailed. You would need to file as the sentence was not appropriate to the crime committed... and that requires a pretty good amount of legal research (to make sure that this sentence was, indeed, cruel and unusual).

