Hi Katy,
Another one to add is please don't belittle them when they are going through med changes and trying to get stabilized on one. Don't say things like, what is your problem, why do I have to constantly repeat myself, aren't you paying any attention to what I am saying? It is hard to get adjusted on a new medication and sometimes things things get a little hairy in the process. Also don't ask him if he has taken his medication today right after something has happened like maybe a irritable time, etc. Ask him that question when he is more calmer.
If he is having a difficult day, ask him what you can do to help him and if he dosen't know, offer him some suggestions. There may be times when he feels less social and you can try to to find other ways to help him feel better by finding something that you two can do together. If he wants time to himself, honor that too. A lot of time I just need to just chill by myself, rest get into my own thoughts, etc.
But always remember what LFW has shared with you about standing up for yourself. You need to teach him that he should not be lashing out at you and that you won't tolerate that. Be supportive. That is what counts.
Eventually, with proper medications things will start to get better.
Please continue to post. We have both Bipolars and those that are marriend/live with bipolars. You'll get a lot of feedback from both sides.