Is there hope at 64?

Hello! I am new to this Website and had an epiphany when I saw Ms. Orlov and Dr. Hallowell on the TODAY SHOW. Hearing them describe the symptoms and the dynamics of a relationship, was like describing my marriage to my husband! We have only been married for 7 years, but it has seemed like an eternity of pain, anger and frustration.  I had even told him in the past that it seemed like his affection ended for me on the very day that we came back from our honeymoon. Two years ago I sought marital counseling, telling the therapist that I was only there to learn to live in peace and harmony as I could not leave the marriage due to financial reasons. My love for him has been eroded away by anger. Anger directed at me, and the own anger I have stewed in.  Since he is a Vietnam veteran I insisted that he see the psychiatrist at the VA clinic. The diagnosis they came up with was PTSD, (AFTER 40 YEARS!) which I am sure plays into his behaviors as he lost both legs stepping on a land mine. God only knows how he has managed so well! The psychiatrist at the VA prescribed Ativan, which he stopped taking due to side effects. Then he was prescribed Wellbutrin and Citalopram. We began to see a licensed clinical social worker at the VA about once a month or longer, all the while not making any progress. Then as I said before, I saw the show and began to realize that perhaps we were on the wrong track. At his next appointment with the VA psychiatrist I asked if there was the possibility that all of his symptoms could be coming from adult ADHD. He stated that that was a big possibility after taking a VERY short history and then sent us on our way with a prescription of Ritalin and instructions to continue taking the Citalopram. My husband is taking, I believe, a 5mg dose of the Ritalin three times a day. He states that his mind seems clearer, but sadly, I am not seeing much improvement. Especially since he implied a few days ago that he was going to commit suicide and then packed up all of his things and left me. Part of me is very relieved, and the peace and quiet has been heaven! However, this is the 4th time he has left me and he has already indicated that he would like to come back! The only constant in our marriage is the blame and threats of leaving.  I don't want to come across as unfeeling or coldhearted, but I want to take my time in letting him return. I am, like so many of you, EXHAUSTED! Emotionally and physically.  By the way, another counselor at the VA called me today stating that she felt that my husband indeed has adult ADHD after taking a long history. Now that we KNOW, am I living in a fantasy world hoping that someone at 64 can learn new behaviors??? Or is this something I should just give up on?

Anyone's insight would be greatly appreciated.