I believe my fiance has lost it i think he is having a meltdown help me?

a couple of weeks ago my fiancé more or less just snapped because of the lack of sleep he had, and I came home and he had OD on sleeping pills he was very irrational , hostile, violent, and frustrated with himself the paramedics had to like tackle him just to get him on the gurney and the Doctor told me if it had been a hour latter I would of been planning his funeral instead of our wedding I love him dearly and I have known him for around 6years but I have never seen him like this b4 in my life I think he just snapped and could not take it anymore, but the other night he was back at it so now I threw them out I am so worried I don't want to have to bury him what can I do or rather what should I do? any advise is welcome expect don’t ask me to leave him because I wont we have been through too much together and plus he was just desperate for some sleep and he hates drugs with a utter hate!!!!!!!!!!!!!!!!