Parenting advice needed-I have fibromyalgia,sleepless toddler and defiant five year old..?

I have had fibromyalgia for around 9 years now.I am so tired all the time and my (passive aggressive)partner won't understand, just thinks I am lazy and won't help myself, my toddler won't sleep, my five year old is hyperactive(diet managed) and is going through a real won't listen phase. I am so at the end of my tether sometimes I would like someone to take her away for a week. Can anyone give me any suggestions for how to make my life easier( I try to FLY, but not doing well at the moment. I am really struggling at the moment, mostly because I feel so unsupported but also because I have awful dental problems at the moment making my sleep even worse.
I love my children and have done my best with them but feel I have reached a brick wall ATM . My partner's lack of support makes me sometimes feel angry at them for needing so much from me when I don't feel I can give them what they need.
My five year old hardly ever eats anything I make her to eat to the point where I just hate cooking.