Op, I am mum to 3 DC's, 2 of whom have extra needs, one with hyper mobility, who has amongst other things PE, BPD, CLD, and LD, tube fed, so I do understand the bone aching tiredness of not coping, and how easy it is to find yourself in floods of tears and wanting to slam the door on your ways out. I have spent more days in tears than I care to remember.
I am fortunate to have a husband who let me go away for the weekend to recharge my batteries. I am so sorry that you have found yourself in a situation where the one person who should be helping and supporting you, is only thinking of himself. I agree with what others have said, he's not easing your burden, he's increasing it.
I am just thinking aloud here, and will apologise if I am repeating suggestions made by others, am also newish around here so don't know any history.
You have 4 dc's all with complex and continuing health needs, is there a children's community nursing team attached to the hospital? Are they involved with you? If not can the paed refer you to them? They have been involved in our lives since youngest ds was born, and I am hopeful they would help you access support packages, and help fight your corner in getting extra support. They will also be able to support training to deal with meds, feeding etc..ours work mon to fri at the moment, although they would be who I'd call in the middle of the night, when ds was blue!! Ours are attached to the children's ward, they also tend to be involved in all the children's clinics such as diabetes, oncology, respiratory clinics etc
Did the Local authority do assessments on all 4 children with a disability? If not why not? Do all 4 children have their own referral? You should also have had an assessment done on yourself as their carer, and your needs as such. Was direct payments suggested as an option? Respite care? The LA here paid for homecare to come in here whilst I went for therapy. We also had homestart too, for a long time I used to use that time to clean the loo, do the ironing, pick stuff up etc.....but maybe this could be an option for you. If your dc's health needs are such, should you have trained nursing staff in the home, then should the health authority be providing you with some form of respite?
What about Opps Class (where I live we have a play group, which is set up for children with special needs, takes children from babies upto nursery age) the staff work with the children to help them learn & as a mum it's nice to be surrounded by another mums who know how crap this all is. My son's paed referred my son to the SN pre-school worker, who referred us to this group and also sorted out 1-1's in pal group/nursery. Might also be worth asking if there is anything like this locally to you.
Your local Authority should run also Disabled Children's Register. We have a card which states the children are registered disabled and helps when it comes to accessing disabled benefits on days out, ours sends out a newsletter which lists support groups, courses that parents might find interesting, how and where to access support.
Do you have a Carers organisation local to you? They too will be able to help support you to access the services locally, they may well also run parents courses, know who and what charitable organisations are around who could support you too.
What about support group locally for parents of SN children?
You will need to scream, shout, jump up and down to get someone to listen to you, I know when your run down and struggling, it's hard to find the energy to have to battle the services that should be supporting you. But the ones who make the most noise, normally succeed in getting what they need!
Wishing you lots of luck