Hi sister, I am so sorry to hear about this situation, I have some experience that might help here;
I was around and had depression when my grandpoppa killed himself (19 I think).
It caused very severe emotional and eventually physical harm to my mom (she started to develop ulcers and mobility issues).
I don't think my mom really forgave him but from where I was I could understand his pain and why he did what he did.
You husband doesn't sound very nice and while I know nothing more of your situation this is awful behaviour.
Your son however is probably completely innocent in all of this.
If you want him to understand and forgive you, then you (and this will be harder than nailing jelly to a wall, but stick with it) need to have a candid talk with your son and try and develop and understanding.
There is no judgement here, I also have a son who I love dearly so I understand at least in part the pain you have.
Good luck sister, I hope find peace.
DBD