Hi there. I've read your posts and you're quite an inspiring and strong person. Despite how your son may treat you you're obviously quite the leader and provider of the household.
I guess what I try to say is that you do have power, influence and deserve the respect and standing of every other carer in the world. It's an unpayed job to look after another person however you see it, and the attitude of your son doesn't reflect on the majority of people's views on your help of your family.
You're doing well, and I can understand how tired you must be.
Be sure to start eating properly, and drink water more than sugary drinks and you'll begin to feel fresher after sleeping. I know sugar is the go-to for a quick fix, but water will help more in the long run for keeping you awake. Three square meals a day will make you sleep better as well, as your body wont be restless from lack of food.
It's a lot to think about when you're stuck in a mindset, but small changes can start.
Looking forward to hearing from you again.