Is it his ADHD or is he just bad ?

My boyfriend returned to work after a month of vacation. We work for the same company, but he works offshore. Sometimes if we communicate ,its via e-mail,maybe the phone. Off work, he has to call, cos its offshore. Otherwise, there's the e-mail. Get this , in his month of vacation, he didn't call or e-mail once. When I asked him after his return, he said he was sick and forwarded his credit card bill and prescription.But I know he was doing a few transactions online for his business ( on the side). So he hyperfocused on that, and forgot to call and let me know he's alive. Fine. His reply also included that his family were also pissed that it could be months before they heard frm him.

I'm been doing alot of reading on ADHD, and would love to say " oh , this is ADHD". But that shouldn't become an excuse right? Normally, I send him e-mails ,to which he replies. We skype ,and he calls occasionally. I just feel that I'm the one making all the contact. Almost makes me feel  desperate. He's been divorced 3 times, with the kids and  all. He's also abused drugs and alcohol. But he's making a change,he still drinks but not to excess I think. Atleast he has a job.Though,he's been saying that it's getting a bit boring for him,the money's good.

This is a long-distance relationship ,turning 5 months old, and my family and friends think I  can do better. It's been a few months since I saw him, unless  you count skype. I know he's done some negative stuff, but what he is now, and will be like in the future is what I want to focus on. Yet, I don't where we are. In the hyperfocus stage, we said "I love you" to each other quickly. Just recently, he said he was crazy about me. But he wouldn't send me that " hi, how's your day been" email ?

I like him, and I think we can see each other, see where this goes. But how do I know I'm not being made a fool of ? He's just opened up on his ADHD, but I don't know if he's following up on his meds. Should I keep making contact or, let him reach out to me ? The thing is,if it's the ADHD,I am willing to work with that,  but if it is plain selfishness, why should I bother ? If I raise this to him,I'm not sure how he will take it. I don't want him to think I'm needy or , I don't trust him.

I'm looking for any advice you guys might have. Any insight ?