ADHD in Men

I've been dating this guy for about a year and a half now.  He is 25 and I am 30.  He is a great guy and comes from a good family.  We have a lot of fun together and i love him very much.  The negative part is that within this past year and a half he has broken up with me four different times.  We were dating for one month and he ended things.  He said he did not see a future for us and that he was a flight risk.  Meaning his job can send him to work in another state.  We stayed friends and then he started asking me to hang out again two months later.  He said he missed me and loved me and wanted me to be his girlfriend.  So for the second time around that we were dating it lasted for five months.  Everything was great until one of my friends told me that my boyfriend gave his number out to one of the servers at a pool hall.  My friend knew the girl and he had said the girl said that my boyfriend was hitting on her.  I was devastated when i heard this.  I was so happy with him and now I had to confront him about this nonsense.  When I did confront him, my boyfriend told me that he was just being friendly.  He also said he doesn't have a lot of friends around where we live since he is not from here and that it didn't mean anything.  For the next three weeks, I couldn't help but think about how he gave his number to another girl and maybe what else does he do behind my back.  So we got into a few arguments and he winded up ending things.  He blamed everything on me and said he just wants to be alone.  I tried to make him see that he was making a mistake and he shut me out by ignoring my calls and text messages.  A month later he comes around for a third time and I just give in to him because I love him.  He told me we can't argue like we did but he wants to be with me and see if we can work things out.  Two months later he left for Florida to work there for four months.  We did the long distance relationship pretty well for three of the months but the fourth month is when he started not calling as much.  I sensed it right away and I brought it up to him.  He started arguments with me and he winded up ending things over the phone as he was in Florida and I'm sitting here almost 1,000 miles away waiting for him to come home.  He told me we can talk in person when he gets home in a few days but right now he is not talking.  This time he totally shut me out.  Did not answer the phone for a week straight or any of my text messages.  He finally gets home, mind you he lives right across the street from me.  All of a sudden I see his bright blue mustang outside his house and I was so excited because I thought maybe he was going to come walk across the street to see me.  But no he did not.  We play on three pool teams together so I eventually started to run into him again.  I gave him the cold shoulder at times and other times I was just civil with him.  A month later just when I started to feel better about moving on with my life he asks me to talk to him in person.  So we wind up talking and hanging out and he told me he loves me and wants me to give him a chance.  He said I am everything that he wants in a woman and that he messed up.  So for the fourth time I gave him a chance.  I really thought maybe this time he did realize and he is not going to be that stupid again to just walk away.  But of course I was wrong.  Five weeks later, which was last weekend, me and my boyfriend got into a stupid argument.  In the argument I told him to consider himself single.  I didn't mean it.  I was just upset with him and my guard was still up because of the recent break up we had.  The very next day I apologized up and down.  He did not want to hear it.  He told me he can't do this anymore and that he thought things would have been different this time around but they aren't.  He said we are not good together and that he's just done.  He even quit our Wednesday pool team.  My boyfriend well now ex-boyfriend does have ADHD.  He had it when he was younger in middle school and had to take medicine.  His father said his son didn't have to take the medicine anymore when he got into high school.  I heard this information last year and I did not think I should be concerned since my boyfriend wasn't on the medicine anymore.  I thought he was okay or maybe outgrew ADHD.  He is very impulsive.  He is always on the go.  He goes to work on his days off.  He can be so sweet and lovable and shows me he cares so much but then there are times where I felt like I didn't even exist to him.  Like his mind was elsewhere.  So my question is, Is ADHD affecting him and how he can have a relationship with me?  I know he loves me.  I just don't understand how he can come back crying and asking me to give another chance promising he will never leave again but then does leave the moment there is confrontation?  I feel like I have been on an emotional roller coaster this past year and a half.  Is he going to come back again? Or was the fourth time the last time?  I' ll never understand.