Lost....needing advice

I have been with my husband for 17 years married for 15 yrs. He had an affair 2014, we reconciled  and moved to make afresh start. Our son (14 yes) was confirmed ADHD just a few short months ago 

Our  marriage has been up and down our arguments the same pattern.

My husband started another affair just a couple of months ago. He said he'd had enough of the marriage and the constant arguments.

I came across the article about ADD and marriage. It was as if the article had been written while in my home. Everything was down to a tee. I sent it to my husband. He doesn't think he has it. I brought the book and ended up  reading it In one day.

It gave me hope that there was a chance to save this relationship. My husband said he doesn't think that with all the negative things that have happened that he can't see himself with me. 

I asked him to stop seeing this other person so that we maybe able to work on our issues. He wants to live a life of seeing other women. 

Is this type of behavior apart of the ADD. Or not.

I do not have the comfort of a family even his, as they believe that even if he has ADD it doesn't mean to say that the marriage is broken because of the pattern.

He said he will read the book and also go to see a counselor that we both went to see. It wasn't a good meeting.  He sends mixed messages I said he is the love of my life,which he reciprocated the counselor asked him to stop because of how it was upsetting me. And that's when she said about the mixed messages. She even asked if he would consider not seeing this other person until we had dealt with our situation. That I was still his partner and it was hurting me. He said he didn't think so.

We didn't speak for 3 days (he is staying elsewhere) he dropped off our son and asked to talk. He can't see use working if we got back together to much hurt. However he did say he would read the book and see the counselor.

He has also seen the pattern at work. 

What can I do  I am still in love with him. But I hurt so much, it feels like dropping out of a race just as you get to the finish line. All the steps are there to rebuild our relationship.

He went away this weekend he told our son with a friend that means a female. Its hard

Should I hold back and see what happens with the counselor and the book. Or should I just walk away. I told him that if there was no reconciliation then I will not be interested in any type of communication, apart from the practical things that can be done via texts. It will hurt to much for me to see him.

Help please, suggestions,ideas, words of advice