Oh, boy!
ok...first off, your son has been through a LOT in a very short time! (not to say you and your DH haven't!)
If it's at all possible, enlist the help of friends from your church or other "support" group to come watch your son with you during the day..meaning, they will hold him and take care of him while you are doing household chores for a couple of hours a couple of times a week for a while. If you and your husband can afford it, hire a baby sitter (teens who can come over after school during the week would be great!) Since you'll be at home with them, you won't have to worry about "security" issues, and "first-time" sitters will gain valuable experience!
Don't expect *everything* to be *back to normal* for at least a couple of months. Your son is still healing, and very much needing to be held by mommy right now. Remember, right now, he's probably thinking "if I go to sleep, mommy isn't near me, and strangers are doing "hurtful" things to me!". Just be patient, and don't hesitate to reach out for some help. He will eventually learn to go back to sleep on his own, but he is scared to do that right now, so it's ok to hold him until he is asleep.
Be sure and keep lots of hand sanitizer around your house, and when people do come over for a visit, make sure they use it FIRST thing when they walk into your home, especially if your son still has some incisions that haven't closed up completely yet. And I would stay home on Halloween this year, to minimize him getting any kind of cold or other virus. You can still buy him a little costume (the little "pea pod" or "baby carrot" costumes are soooo CUTE!) and take pics of him in it.
My oldest son had MAJOR kidney surgery when he was 2 1/2, so I know what you're going through, and it is very scary. Please feel free to call me if you have any questions or just need to talk. My phone # is ###-###-####, and I'm a SAHM to a 2 1/2 year old and a 16 year old (both boys).
Remember, too, that you need as much rest as your son does.
Blessings, and warm fuzzies!
~J.~