Is that the only response he has sent you? There is no mention of him falling asleep or any address of his other marginalising behaviours. I would be very angry. I think this is more than unhelpful - it compounds your experience of not being seen.

"I am concerned about you" would fall very flat with me in the context of his other behaviours and comments. Ordinarily, I am enthralled when my therapist says similar things to me. I romance our relationship and I get giddy with the magic of her. Saying this on the back of falling asleep in session would ring very hollow and I would be questioning her authenticity. "I am concerned about you but not enough to stay awake" is what I would hear. But then I am a petulant child in many ways, hopefully you are more emotionally mature!

I feel sad when I read how you are trying to maximise your chances of maintaining contact with him and continuing your work with him. I have commented in one of your threads before on the issue of money and therapy so I won't labour my point, but he appears mercenary. How is he meeting you? All I hear is how you are trying to accommodate his boundaries. As someone else said, he has a duty of care towards you.