I haven't turned into a "monster". But these short months I've been on Keppra, my fuse is REALLY short. I'm an irritable old man in a 25 year old body to begin with, but when I started the Keppra it wasn't fun for my gf. She is a worry monger and I don't spend anytime thinking about things outside of my control like my epilepsy. I can't speak for your husband b.c I obviously don't know him, but I'm a person that NEVER takes medication and now for 2 years I have to. I HATE the fact that epilepsy forced me out of my job and resulted in a medical discharge from the Air Force. The fact that I'm now catered to is always in the back of my mind and I hate that too. I'm not making excuses for what has happened and I'm not trying to justify it. But for me, knowledge of the fact that I'm on medication is the worst side effect.
My gf being the worry monger is constantly asking me about my health and to put it lightly I don't like it at all. I've thought of going to someone to talk to about the anger issues, amongst other things, but I can't afford anything of the sort at the moment. An epileptic with no health insurance. If you haven't yet, and if you can, I'd say step one is talking to people that have known him for as long if not longer than you, parents, best man etc. Get their input.