Wooden I think you'll just have to take the bill by the horns and tell your dd that you are now in control of what he eats.
No more vegetable wraps, no more him preparing lunch and no more refusing dinner.
You prepare all the meals and snacks.
He will kick off, he might become aggressive, he might try and run away.
You just have to be consistent and not back down.
Pps have had kids put their feet through oven doors and a car window screen when getting them to eat. It is very literally a battle. My own dd used to head bang, tie ligatures around her wrists, run out of the house...
As he is autistic get the autism to work to your advantage, does he like routine? Does he like rules? My dd does so once I explained the rules to her she reluctantly accepted them.
It is hard but he is not well enough to make any rational decisions about what he needs to do to recover. You have to make those decisions for him.