Whenever complex situations arise, and it impacts a family unit, the first thoughts always turn to the children, as a parent that is natural. Hats off to you and your husband, reflect on what you have achieved so far and the journey you have taken, together, you have 4 children, that is something to be immensely proud of.
Reading your post, I am not trying to justify your husband's behaviour, but know that it is those that we are closest to, are the ones we turn to and often lash out at, use as an emotional punch bag, when things get too much.
Life is a journey, and as well prepared as we can be for every eventuality, unfortunately there are always unforseen situations. We all think about the future, but worrying about it takes energy.
Being sleep deprived, not eating properly, feeling low and down along with the stresses of every day life, you too may become unwell, and again this relates back to my first comment.
Being emotionally controlled in a relationship is not a relationship, I am not suggesting you give up on what you have together, but you do need to make it clear that this is severely impacting on the whole family, and that it needs to change.
Communication or the lack of it is the cause of and solution to all problems.
You really should discuss this with someone ithink your doctor would be a good start.