4x4 problems

I was driving my truck the other day during a snow
storm. I came up to a stop sign in 4wd. As I
accelerate my truck started to hope and bounce.
My abs light came on then service break system.
Those dissapeared a minute or two later. But truck
kept jumping and making grinding noise when tires
slipped in the snow. I can hit the push button
controls and go threw all the controls for 2wd, auto
4wd, 4hi, and for low, also can hear the motor on
the transfer case moving but now all I have is 2wd
no matter what light is lite on my push buttons. I'm
thinking something broke in my transfer case but
not sure