7-8 weeks , always sleeping,slinding back legs half time

[Sabrina03]

Hi , so I am new here and I really need to know what is happening with the baby. When I got him he was playful , likes cuddling always on me or my husband. Since 2 days he is always is the bigger cage doesn’t want to go out . I have to give him food and milk inside the cage or he hides in his blanket if I try to get him on me. I notice when I found him a week ago that sometimes he was sliding his back legs instead of walking it. And now like I said since 2 days he is always sleeping wakes up for food or milk I try to give him a little low inside the cage with my hand only wants to play by bitting my fingers (not hard). I am really concerned by his new habit . Doesn’t seem normal he is suppose to be more playful I guess.
I started as suggest yesterday calcium but not much of a change ...
waking up :
2 cubes
Not long after first milk
he drinks fox valley milk
11-12h
2 Small pieces of veggies
And a cube
4h
An another milk drink
8-9hpm
1 fruit and milk again
Pls help me I don’t know what is going on with him but is behavior is strange I know something is up....
Picture are from when he was ok
Can’t post a video of now ... and sorry for my English not my first language..