Hey Lost
This is so sad, I feel your pain. I was in a relationship with an alcoholic for 13 years, I eventually left, the controlling and deceit got so bad, he then tried to control my children and blackmail, so I left. He took his life, when I did eventually start a relationship after years later I found my new person he had an addiction to cocaine. I came here on my knees and these amazing people helped me
you need to stay away from him, truly, it will only make you sick in the very long run. Journal all these thoughts out. Block him. This new woman, she is more than likely an addict too as that is where they find common ground, if not she will soon learn too, I feel sorry for anyone who finds themseleves in a relationship with an addict.
The relationship you need to focus on is with yourself and your children. Get therapy if you can and journal. Breathe and meditate. I know it hurts like hell. I promise you will get through this if you allow yourself time and limit contact as much as possible
B x