It TOTALLY sounds like he is alexithymic to me

I think I am alexithymic and the thing you said in your original post where he is really disconnected and stoic but then got choked up about saying something to you when he is upset sounds a lot like me. That is the pushed down emotions swelling up out the the giant hole that has been dug to contain them I think

And with the conversation you describe I always have the need to transmute emotional problems into practical ones... like trying to address emotional issues with logical explanations and concrete action-based solutions.

Even if you feel like he isn't supportive enough in an "emotional" way to you sometimes the fighting through his back pain to do the chores because he knows you are hurting physically is probably very illustrative of his love for you (and if necessary should be accepted in place of mushy-type romantic stuff which may outside of his emotional range). He might not be super-romantic but I bet he loves you is loyal as hell, would surely jump in front of a bullet for you without a second thought