Whathappensnowthen I am really sorry, your situation sounds terrible.
Please speak to women's aid and make a plan to be free of your controlling alcoholic husband and this other man who is using you for his jollies.
I do not blame you, you have been damaged by these experiences and now are kind of drifting and potentially about to damage others by your actions.
Please use this thread as a wake up call. This affair is not making you happy, it has the potential to cause massive upset to this other man's family, and to yours. And it kind of muddies the waters. Please find out how you can leave your controlling alcoholic husband. Is he abusive? Control is abusive really so anyway, it is your choice, but if you want to start a new life, away from both these men, who are controlling and using you, then please get some real life help and move on. You could choose to live near your parents but not actually with them.
By the way, you speak about your children in a very dispassionate, rather cold way. I am not being critical, just saying. It did make me wonder if you are suffering from depression. If you feel this may be the case, please do also speak to your doctor.
It is not your children's fault you had several of them and now feel trapped in your marriage. BUT it is your husband's fault that he has made your life so miserable. It is not either his nor the children's fault that you have chosen to have an affair, that is your choice. Please choose to end the affair, re-evaluate your marriage and life and make plans to move on if you feel this is right for you.
This is all IMHO, and said with care, because I feel you have had a really rough time BUT also that you can take your life back, you can be back in the driving seat of your own life, YOU CAN DO IT. 