I'm please you have sorted the NDIS, a major triumph.
You sound very pressured, and your whole post is taken up with arrangements for you husband. I quite believe you when you say they are beneficial, and it is obvious you do a huge amount. When not doing that you are trying for others, in this case babysitting.
To break down crying is no surprise, the demands you make on yourself are pretty total. I may have mentioned this before but will repeat it any way (walruses have limited mental processes:) I think you are wrong to protect your husband from the plain truth that his condition affects both of you deeply. As an adult, even in such trying circumstances the possibility of lending support may well be a source of satisfaction and pride. And to do that he does need to know how you really are.
A few times in my life, including my first partner's long illness and final passing, another time when an offspring was overwhelmed with grief, and other times too I've been helpless to affect circumstances, and felt powerless and frustrated at the time, but now know how much my efforts meant. I am grateful to have had those opportunities.