My H isn't as big of an ***** as your fiancée, but I know the feeling, that horrible trapped, helpless feeling
They are sad pathetic people, those men (and some women too I know ). The only way they know how to cope with themselves is to beat somebody else down. And they generally refuse to do anything to help themselves, preferring to blame anyone who'll let them.
Stay strong SP. Never give up on yourself. Remember you are so much stronger than your fiancée - you can face yourself while he cannot.