A really annoying effect from that crap is when I'm not on it, I ...

A really annoying effect from that crap is when I'm not on it, I feel very aggravated at every little thing, and just inside I feel grouchy. But when I get some in me, I feel very happy, and everything is alright. The problem is you have to have it everyday and that turns into severe addiction, and I really hate that word, just like smoking. Is this a usual effect for everyone, what is the chemical doing this? Also how long does the sickness of morphine last for if you go off it?