I think you need some support to deal with this manipulation and emotional abuse. Have you told anyone about the suicide threats , ie, a soliciter , his parents ect ? Do not collude in this and keep it a secret, i made that mistake and i regret it now. Bring it out into the open, hes not your responsibility.
The last time my ex threaened suicide i said i was ringing the police , and i meant it. Hes never done it again.
Ex or not, its hard to break free of these emotional abusers once theyve got their claws into you .