I think we can all relate to the rage thing - anybody who's bipolar has had it. It comes with hypo/mania AFTER the euphoria, you know when you go higher than that. I dont know why every article you see describes hypo/mania as euphoria, it sure isn't for most people except on the way up or down, then it's irritability city and rage! The worst!
Its hard to believe you are having that problem considering the meds you're on. You are not stable, or else you wouldn't be having that, you need to call your doc today and get an adjustment, your lithium level may be nontherapeutic. when is the last time you had a blood level drawn?
Or, if that's not the case, something else needs to be adjusted/changed altogether. I hope you feeel better, that sucks!