I really think that even the best of men don't understand what it's like to be a mother. I have a wonderful DH, but if I let myself dwell on it, I end up hugely frustrated because he sometimes just DOES NOT SEE when I need help! So I try to focus on the good parts - and sometimes reading through the relationship posts here on BB can make me pretty thankful for what I've got! And, if there is something in particular that I really would like him to do/not do, then I try to find a quiet, non-stressful time to gently talk to him about it.
I'm not telling you to ignore your issues with your DH - just don't let them become bigger than they need to be. I don't know what the trouble exactly is in your case, but don't let it ruin your relationship if it doesn't have to.
And, for what it's worth, WE understand what mothers go through! We'll sympathize with your worries and stresses, and really know what a mother's day is like with little ones.
All the best for your DD's appointments, and you and your DH.