new owner looking for advice

Hello, I recently became the owner of two 10 week old ferrets.

They've had a bout a week to get used to the new area and things are going quite well, except for the things that are not working out. Those are going horribly.

The small problem is using the litter box. I'm using decent ones, with a very low cut on the front so they can easily back up into them. The one in their cage at night they use no problem. The one in the living room (where they free roam during the day) gets shoved aside so they can do their business behind it, and every other corner in the room has been used, no matter what I do.. blocking it off doesnt help. moving them to the litterbox doesnt help. Idk what to do (also it says everywhere ferrets don't want to be doing other things in the area where they do their business. Mine sleep in the litterbox..umh...)

The biggest problem, which I know many have, is biting. I adopted these two from very well respected ferret owners who handled the babies every day to get them used to it. I'm trying to continue this. For one ferret, this is no problem. She's okay with me picking her up, even if it's only for a little bit. That's okay, we can work up to cuddles.

The other is different. I have not been able to pick her up without being bitten. Constantly. She is conforming herself in every direction possible to bite at me. No matter where she can reach. It's continuous and vicious. I don't know what happened. When I got her, I could hold her. She was already biting me but it was more like nipping my fingers. That was fine. Now she is breaking my skin at every attempt I make. And I only pick her up when she comes to me...and I'm still forced to put her down because I'm just in too much pain. All the "How to stop your ferret from biting" articles and videos online don't seem to help--It even feels like its getting worse.

I don't know what to do. I love my ferrets so much already, but I can't keep this up and don't want it to get to the point where I'll always be too scared to pick her up. Please help. Any advice is welcome.