2001 Dodge Ram Transmission Problem

My transmission on my truck has been acting up here lately. Most of the time it will either shift from second into third on its own or I am able to do it dropping down into second and then putting it back into drive from shifting off the column. This morning I went on my way on to work and it wouldn't shift at all going from second to third whether the truck doing it or myself. As I was trying to drive home I couldn't go any faster than 25 mph without it shooting to about 4000 rpm's and acting like it was in over drive. So what I'm wanting to know is. Is my transmission totally done for or is it as simple as reconnecting the battery or changing the fluid and filter? I know its tough without looking at it but any information helps. Thanks.