Questioning Sudden Mood Changes

Now that my meds are adjusted and have had time to kick in, I can look do a daily assessment of myself and I've noticed I have sudden changes in mood.  I can be somewhat ok and within minutes or within hours become very agitated and very critical (sometimes angry but not violent). This can last for days or even weeks (very hard to live with).  Then suddenly within one day I can become elated and this will last a day or even more than a week.  Then, within minutes or a little longer, my mood will suddenly drop to very low where I cry very easily or for nothing. I'll start thinking about death and suicide or want to cut but don't do it.  I get anxious about this because I fear I'll go back to when I was extremely depressed and on the verge of doing final harm to myself.  Then, within days to a bit over a week, I'm back to somewhat ok again.  This whole scenario was very extreme when I first started meds for  major depression.  Now that I'm more stable, its not as severe.  It does remind me of various times during my teens, late 20's, 30's and 40's and those incidents were not violent in nature but not normal--but I was very good at "hiding" myself--just moody.   Or could I just be moody -- too much to hope for?