Re: never let me put her down
At 5-6 months, my kid was the same way. If I put her down, she screamed. I was wearing a 17 lb child in the Baby Bjorn day in and day out. I thought my spine was going to collapse. DD eventually grew out of the "I don't want to be put down- EVER" stage, but it took a couple of months.
I totally second the advice to check out The No-Cry Sleep Solution. Even if it doesn't work for you, at least you feel like you are doing something!
If you're getting physically worn out from wearing your child constantly in the Bjorn, you might want to move up to an Ergo carrier, which I found to be easier on my back (particularly in the side/hip-carry position).
If you find that you are getting emotionally worn out, then do not feel too bad if your child ends up crying for a couple minutes while you step away and gather yourself together. She won't end up psychologically traumatized.
Hang in there! This ultra-demanding phase will pass.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"