It looks like the others have had some good suggestions. The star chart is an excellent one. I can remember my sister (when she was still talking to me lol) telling me about it for my eldest. I found it hard to be consistent with it, but kids do love them hey. We used the reward of buying a toy I think, when it got to a certain number of stars.
It sounds like you're really worn out by all the caring work you're doing.
You absolutely have to look after yourself, and do whatever you can to make life as easy as possible. The fruit thats easy to get is great, and you've thought of so many ways to work around the difficulties for your son. I'm guessing all the professionals you deal with have good ideas too.
So what do you do for you? And do you show your kids that you are a human being with needs too?
Maybe, I dunno, maybe you can think about changing it up a bit, every now and then. Like a picnic for dinner, outside on the grass.
And maybe you can encourage your son to do some things for you sometimes, so it's not all about him. Let him bring you pancakes, or pour your milk on your cereal. Remember to encourage him and take the time to enjoy his achievements, which can be sooo hard when we're tired, but could actually help you to connect and be present. Beware the zombie state!
I had this amazing drink at my friends house recently, it's like a b-vit fizzy tablet with guarana in it? Not sure if it was that, or the zinc tablets, or the vit c, but I felt great! After feeling really tired too. You mite need some B vitamins...
The stuff with your daughter sounds really hard too. My friend has a d with down syndrome. She really struggles at times, and found the yr she turned 18 to be the most challenging so far. There's just so much she wants for her, and the system with all it's assistance is really quite limited. It's such a challenge for her, and for you it sounds like.
It sounds like you are feeling really responsible for how well your daughter does, and what happens after school. With my eldest i remember feeling quite anxious that she wasn't doing well, and then she started to self harm and that really threw me. If I could go back, I guess the first thing I would tell myself is, Don't worry about school! Protect the relationship, make time for her, love her. She was making decisions I didn't even know about.
Your kids are lucky to have you.
Take care, of you,