Dear B.,
My mother has a very similar disorder and her diagnosis has been flipped back and forth from Bi-Polar to Phscizso-effective (a mixture of Bi-Polar Disease and Phsycizophrenia (sp?)) Anyway, as a child of someone with this type of disorder, I can tell you this IS taking a toll on your children. My mother raised my sister and me alone, our father left her when I was 3 yrs old (mother was still pregnant with my sister.) While my situation was a little different--we didn't have a healthy adult helping our mother look after us but she also was never violent, just delusional--I can tell you that most of my childhood was really screwed up; to put it lightly. It took me a long time to realize that my mother was not normal, that the things she thought and the visions she saw were not real. Her mood swings kept her from ever giving my sister and me the kind of stability and consistency that we needed from her and to be honest, I've done a lot more to raise her than she has been able to do to raise me. She kept custody of us by basically hiding from anyone who might be able to tell that she wasn't really capable of raising two children on her own. Even now that I am grown and have one of my own (a beautiful 5 mo old baby boy!), I still carry the burden of caring for my mother. When she has her episodes (which usually last for months but will only occur once every year or two) it is my responsibility more than anyone elses to make sure she takes her medicine, doesn't harm herself, and goes into the hospital under round the clock suicide watch if things get too bad.
I guess the point here is, unless you are committed to your husband enough to be willing to be his care taker, and to have to hide his behavior from your children, I believe you should leave. Even more than his disorder, staying in a relationship that you are not happy in will take a toll on the kids. You should lead by example, if you wouldn't want your children to stay in an unhealthy, potentially loveless relationship, then don't set that example for them.
I wish you all the best. A decision such as this is likely to cause much heart ache but I believe that if you have been strong enough to keep your sanity while being married to him this long, you are strong enough to make this choice and do what is right for your children.