Husband Eternally Manic

My husband has been showing signs of mania for a couple of months now. I'm emotionally numb and feel in constant state of shock.
He was diagnosed last summer after a suicide attempt during a psychotic episode. He tried to strangle me first telling me "this is gonna be the day you die" I was able to knee him and break free run from the house in nothing but my underwear. After 3 months in the hospital he came home and has been taking his meds ever since but he seems to constantly be "high" on himself. His ego is incredible. He doesn't seem to have any empathy for what he's put his family through. We have a son and a daughter that I've barely been able to care for because his constant mania drains me to no end.
I keep hearing that eventually he will come down to earth again but I'm not seeing any signs this will end anytime soon. He left yesterday after telling me that he just needs to get a way for a while to find out how he can manage on his own. I guess I should be grateful but I'm left feeling like I don't know what hit me. Up until last year we had a great marriage (normal ups and downs but nothing so dramatic) he is/was my best friend.