1997 se problems going form 2h to 4h

[jonasp25]

After bringing it into 4h going about 20 mph, it wouldn't go back into 2h, the green light on the dash would stay on, and the car stayed in 4wd. when I take my foot off of the brake, it doesn't move, and if it does, it goes very slowly, if i accelerate in the 5mph range i feel a lot of rumbling under the car, driving above that is fine. I have never had any problem like this before. Do you guys have any idea on how to fix this?