This will be your lowest point lovely, there is only one way for you to go now and you will see light again, I promise.
Your H treated you so badly, the drinking, the prostitutes, the sheer wickedness in the disrespectful way he treated you and your DCs.
I have felt the feeling you are going through a few times, it is utter despair and so many people on here can support you. It is important for you to have RL support as well, is there anyone you can call on?
When I thought I wouldn't see the morning, I called the Samaritans and they helped, I had them phone me every night for a week just to see how I was. If you feel like that again, please wait 24 hours, phone someone, come on here, we'll see you through.
Have you seen your GP? Do you think some medication would help in the short term just to help you get through this most painful time?
My DS gets me through. I always try and have it in my head that no matter how much I miss my H, if I wasn't here, my DS would miss me 100 times worse than that - forever - and his pain would never go away.
None of this is your fault, it is your H's weakness and refusal to deal with reality.
Crying is good, it's a way of coping and mending yourself.
Stay strong lovely, baby steps x