My husband has bipolar...

We found out he had bipolar when we had our 3rd child. Our realationship has always been a roller coaster. He is the love of my life and I would do anything for him. He is a good dad most of the time and can be a loving husband. His biploar has been hard on us. He thinks stuff that is not true and can be angry and mean. Most of the time he says he is going to leave. When he gets like that he puts all kinds of stuff on me. Like all of my flaws. He does not get viloent but he does tend to look at women and chat with them online. His is more of a sexual nature. He says he loves me but needs to find himself. He has cheated on me before. Is it bipolar or is it him or me? Does he really love me or am I a crutch? I beat myself up everyday for not knowing what else I can do. He is leaving this time. Moving in with a co-worker who is going through a divorce himself. I found out he has been wanting to meet women offline. I feel so used and helpless. He is lying to me and I don't know how to get him more help. He was on meds for a few months then came off of them. The doctor switched them and he still has not gotten back to the point where he was a month ago. I wonder how long it takes for the meds to kick back in after ones been off for a few days? His doctor can't tell me anything because its confidential! My husband thinks he can fix himself. I understand how all of you feel. I wish I could have a magic wand that made this all better for us. I am so desperate right now and I don't like that feeling. I am loosing the love of my life and I am angry, sad, confused, lonely, afraid. I pray everyday that god to guide my life and I can't help but loose faith sometimes. I hope i can get some advice on this. Thank you for letting me vent!