J.D.
L.,
The mantra I have learned about parenting is this: This will get better, right around when he does something else horrible! Each phase of difficult behavior ends, only to be replaced by something more annoying he's figured out. Each developmental challenge gets resolved, only to be replaced by learning to do something else that's challenging and frustrating and worrisome. So, yes, what you're going through now will get better, and this stage will end, but it will be replaced by something else that drives you nuts.
I don't know whether or not lead poisoning has an effect on behavior, so I can't answer that one for you. However, your son is not whiny and fresh because he hates you ar blames you for his medical issues. He's those things because he's three, and that's what they do. The healthiest three year old in the world is combative, defiant, and generally difficult. It's the nature of the beast. Some people get lucky, but most don't. This is the age where our kids learn to be independent in wants and feelings, and having some control over life is their primary objective. So they throw tantrums, hit people and pets, yell No! while they reach for the cookie in your hand, etc. That's just the deal.
Yeah, he'll not be three someday. Then he'll be four, and think he knows EVERYTHING. After that, he'll be five, and it's time for school and all the fun that comes with that. (That's not how my teacher does it...ARGH!!)
It just keeps coming. Someday he'll be 16. Wanna think horrible thoughts? There you go. Sex, keg parties and driver's licenses.
What you need is a girlfriend who's in the trenches with you. Someone who knows where you're coming from, who you can call and tell what horrible thing he said or did now, and will laugh. Then you can laugh. That's the whole key. Then she tells you what her kid did, and you laugh at hers. It makes all the difference.
The sad truth is, L., it's never going to get easy. Kids aren't easy. But they're only little once. Savor the little moments and really LIVE them, because you'll never get them back, and they're what get you through. If he doesn't fall asleep in his own bed independently, build a routine aound what he is doing, and savor that time. My son is the same way. Either he falls alseep in my lap, or I sit next to his bed and hold his hand while he drops off. I've tried everything to change it, and it's just not working. So I've built my evening around doing that. Someday he won't want to lay in my lap, and I'll NEVER get that time back. So I let him do it. Sure it's frustrating when I"m tired and and just done playing Mommy for the day. But one of these days he's going to figure out that holding Mommy's hand is for babies, and that whole part of his life will be gone. And it's going to happen long before I'm ready. So I take it when I can get it, and remind myself that this too, shall pass.
So, when your little man is sleeping, however he gets there, and all is quiet, make yourself a martini, grab a book, and sit in a hot bath. And take one minute to think of 3 things he did that day that melted your heart. It's remembering those that will keep you ready to get out of bed the next morning and do it all again.