Some thoughts. Forgive me for going through this stage by stage - it helps me to think.
"I have pneumonia". Goodness me, you'll have been behaving differently even if you don't realise it. That's a big stress for any ASD child. And even small changes of routine if not announced and explained can be a really, really scary thing - like finding ourselves on a mountain we've never seen before with no ropes or handholds and a thousand foot drop below us. To you, it's just a small change, but to us, it's just horrifying until we've seen it hundreds of times and can get used to it.
"DS has been not well." This will tip just about any and all of us into meltdown or shutdown, and we're really bad at describing why.
"he refuses to eat most foods, even try them, if he does try them he usually gags and spits them out"
Sensory issue. Taste, texture, hot, cold, smell...yes, these are huge things for those with AS as well as autism. He's struggling to cope with foods that taste like eating a poisonous brillo pad to us.
"DH gave him juice to sleep with the other night "
Change of expected routine. No ability to think about why this is, so now he's not at all sure what's expected at night. With you not well and him not well, I expect this was a 'final straw' for him.
"we had dinner before on a picnic on the floor. and we usually eat it at the table"
Oh my. I can feel myself getting unsettled, and I wasn't even there. It's new, it's different, it might happen again unexpectedly. Food equals table and chair, and now it equals floor. Drink equals water/milk, and now it equals juice. I can see that his whole world would feel as if it was totally scarily changing.
"he got more and more violent and distressed."
Yup.
"he screams dont look at me, talk to me etc"
Desperately trying to reduce the sensory overload whilst he's not well, and get some sense of normality back again. He's trying to get you to do the things that would help him.
"It took another 2 hours to get him to take the medised as he doesnt like the taste. "
For us, a medicine that tastes bad to other children is like being fed pure acid. His observation would be that you are trying to kill him. I know you're not, but to a child that young with sensory issues, this is the reality of how it feels.
"We got into bed and fell asleep." Now he has you to cope with in the bed. You move, you wriggle, you're hot. More sensory things to deal with. More overload.
"An hour later I woke up because he was kicking me.. hitting me" Yup. He's trying to say "hell, the sensory overload is so much, I need everything to stop - all the hot/cold, all the changes, all the textures and sounds and etc" Your breathing is probably louder than an express train to him. Every time you move, it feels like an earthquake. It's so hard to explain how our world is different to yours.
"DH came in " And now there's more sound, more social information being added to a totally utterly overloaded system.
"He wouldnt let us touch him or talk to him and we had no idea what was going on
he crawled around the room crying and sobbing "
Yup. He probably would.
"I held him on the bed - he was in front of me, his back to my tummy - he was between my legs with my arms & legs wrapped around him and I held him there until he fell asleep. "
Eventually sheer exhaustion overcame the pain of all of this for him.
He needs his routine back. Or really, really clear advance information about what will change, how long for, and when it will go back to normal again. And he's not well and probably will turn out to have an earache or something similar which he can't explain.
You could do with that diagnosis and some expert help in setting up a system for him.
Please don't feel bad about any of this. Every parent would do what you've just tried to do, but handling us when we're not well is really, really difficult and often the exact opposite of what you think.
If possible, a really quiet corner with a something to wrap himself in. No eye contact, no talking to him. A favourite toy or activity. Take his temperature to see if it's that. Use pictures not words to convey information to him if he's struggling.
And have a well deserved cuppa. Goodness, you'll need one.