Abrupt end to our relationship

Background: Relationship for 2.5 yrs. Lots in common and we were together or else email and talking on the phone. We had a strong attraction to each other. We were eachothers support. He started his own green company that keeps him stressed literally 24/7. His job is his life. Diagnosed with ADD a year ago. Takes Ritalin. He has read books like Driven to Distraction, but unfortunately, during our relationship, we never discussed how this Diagnosis impacts us. He was relieved to get the diagnosis, but i don't think he thought he had to enlighten me on the subject and in hindsight, it would have helped a lot in relating and communicating to him. I am not sure he has taken the time to work thru his anger and what affects over the years ADD has caused him.

What Happened: After a party, he contacted me to get together and I was upset that i had not heard from him all day. He then proceeded to come to my home in an angry rage saying "he is done", "can't do this anymore". I have never seen him so angry.This came as a complete surprise and shock to me. I was so confused as it didn't make any sense. He was like a brick wall and would not listen to anything I said to try and work it out. For the 2.5 yrs we have been together he was completely into me and wanted to spend his life with me and my 9 and 12 y.o. He wanted more than anything to be a part of my life. After he ended the relationship, he began seeing someone immediately and I know he was not eyeing her, she was just a relief for him and an uncomplicated escape from his work and relationship stresses. He only got together with her for 1 month and it is over.

My Reaction: I pleaded with him to try and work things out, but it was like he wouldn't listen. H e was a brick wall and nothing I said could change his mind. I sent him letters saying how much I love him and want to make plans for our future. He just kept saying no "we have to move on" and go our separate ways. He said he did not want to see me for ten months as he thought I would "lure him back into my sexy web". Why was he trying so hard to get away? I sent him a dozen roses, he returned them to my door. I became angry and sent him many hurtful emails to get back at the pain he caused me.

He ended the relationship at a hard time already in my life. I lost my job previous month. Enrolled in an intensive online course to improve my skills. And then he dumps on me. He seemed so stone cold.

As a result of all of this, I lost over 20 lbs, couldn't eat, lost all motivation, I saw a psychologist (with no insurance), started on anti depressants. My mother needed to come and stay with me for a week. I have never cried so much in my life. Had trouble caring for my kids. I was a mess. I just could not understand this. He didn't make any sense, but he seems so adamant to stick to his guns and not be lured back.

I racked my brain and finally, I realize that it was his ADD that ended our relationship. I sent him an email to this affect along with links to articles about ADD and relationships. I also said i cared deeply for him and I was willing to work on this together given his ADD and seek help together. No reply.

Can anyone help me and tell me if this is typical add behavior in a relationship and do you think he will come back? Has anyone experience this abrupt ending that made no sense and seemed odd?  Is there anything I can do to salvage our 2.5 yrs together?

What do you think the prognosis will be? Should I forget him. I have now read myself to death on ADD and relationships and it sounds hard and challenging also for the non-adder. Do I want that in my life? But he has a heart of gold and he is fun to be out with and I love him so much. This breakup surprised me as to how much I love him, I was a complete mess. I don't know how he would be to live with.