((((Hugs)))) welcome back we joined here around the same time. the pain your feeling is very obvious in your post and it's good you got all those thoughts and feelings out instead of keeping them all bottled up!!
I think it would be a good idea if you blocked him from your Facebook and don't go back near his page it only hurts you. It doesn't hurt him!! I'm like you in many ways keep hurting myself by contacting him, but I'm hurting myself by wanting him to make everything better, he can't he's ill and the sooner I accept this the sooner I will reach acceptance and move forward on my recovery. Every time you look at his FB page you are re opening wounds that haven't healed yet. I don't know how old your children are but are they off an age where you can say to them to not tell you about dad and his gf and what they are doing and only tell you about anything that upsets them or worries them??
I understand the one night stands hoping to fill a void and erase the hurt you feel but I sense from your post that it's not working. I could be wrong but I also sense that your not ready for a relationship however nice this guy is and is it not better to let him go rather than hurt him by having one night stands.
no one can fill a void within us only ourselves and I know for me definately I'm not ready to be with anyone else not until im happy within myself and reach a point where I don't need anyone elses validation, approval or love to feel happy. If I find someone when I'm ready who will love and care about me that will be a bonus and should add to me as a person not consume me.
You can and you will come through this take it one day at a time and keep coming back and posting don't keep everything bottled up!!