What is the best approach when ADHD partner is distant?

Hi all - great site!

First time on this site and I'm finding it verrrry helpful thank you! I'm in a new relationship with my boyfriend of 6 months who has ADHD, on top of that we live 4 hours apart but we do get to spend a lot of time together, usually every fortnight for 1 week. He is finding the changing routines from when I'm there for the week and then gone a challenge, as do I, but I have children to come home to who keep me occupied whereas he lives on his own so it's a little harder for him. He can be moody or 'distant' at times due to lack of sleep, pressure from work or our routine shifts...when he gets this way on the phone I find it difficult to not take it personally. I'm learning not to ask if I've upset him as this seems to bother him, and he can't understand why I would ask that. He's a great communicator but I have to pick my timing and wait until we're face to face, otherwise we end up having a disagreement, and he says he gets tired of the introspection....which I understand, but I find I have to hold my tongue a little which can be tiring.

I want this relationship to work, he is a good man and I can see he struggles. My eldest son has Aspergers so I have a fair insight into the challenges of having a mental 'disorder' as such. I have a lot of empathy, patience and understanding but I do get a little overwhelmed by it at times so I'm learning new strategies to cope.

My question is this: when we're apart and on the phone (which is every night), how can I best handle his emotional 'distance' so that I don't take it personally? I'll feel like he's cranky at me, which I know he's not, but the tone he uses and the shortness of his conversation leave me feeling otherwise. I'm a strong woman but I can be fairly emotionally sensitive, especially since I miss him when we're apart....do I just have to take a can of 'harden up' or are there other methods that can work? I find if I can make him laugh it helps. Humour always helps hey?!

Any suggestions or advice would be great to hear!!