My mother has tried to hang herself twice, she’s been in and out of psyc wards all my life.
If your dh commits suicide - it is not your fault and you should never ever take the responsibility on of being the ‘rescuer’ or the ‘life saver’. If someone wants to kill themselves they generally do it first time round of they really mean it.
He cheated on you because he wanted to and didn’t think you would find out because if he wanted to ‘self destruct and destroy everything’ he would have told you personally.
He cheated on you and because of his depression you are not allowed to devastated. I can guarantee when he gets ‘better’ you will still not be able to talk about it because you will be accused of ‘dragging it all up when he has done so much work to heal himself’
You need to think seriously and honestly if you actually still want to be with him. You have to put YOU first because actually your the real victim in this.
If you still see yourself getting old with him then let it go. Get past it.
If you can’t see yourself in a happy future with this man then you need to start making yourself financially independent. You are well within your rights to withdraw support, you don’t have to nurse him. He cheated on you and keep reminding yourself of that.
My mother got away with so much because of her fragile mental health. She’s still alive and well despite the failed attempts and hospital admissions.
Depression Fallout’ is a brilliant book OP* and I really recommend you read it. It discusses what happens to the family unit as a whole and the spouse of the person that has depression.
Good luck and please don’t forget your allowed to feel any emotions you have right now. Your not a robot 