The suggestions to see a therapist are good. I don't have any idea what meds you might be able to take; check with your psychiatrist. If you go to a therapist, maybe you could do some sessions with the family members that are having difficulty coping with your moods to help all of you cope.
See a doctor or thearopist
I would talk to your psychiatrist to see if there are any medications that are safe to take while pregnant. You may not have very many options as far as meds go though. Maybe you could see a therapist if you are not already and they could help you with some coping skills.
See a therapist, if you aren't already. They can help you with evaluating what you are doing and teaching coping skills.