'94 Eddie Bauer Explorer Tranny Troubles

My '94 Explorer will not shift right when cold. It takes a few minutes to shift up out of first when you take off. After it warms up, it's fine, doesn't do anything weird. Today, however, when I put it in reverse it made a horrible grinding noise and jerked every few feet like it may just not go anywhere at all. Put it back in first, then second, then drive, and it was fine. Got home, backed up just to see if it would do it again. Sure enough, it did. My question is why, and now what??? The truck has about 209K miles on it, documented maintenance (good), and has run wonderfully until this. It started this craziness after a pulley popped off, and the belt and that pulley were replaced. The next day I started it up and it started acting goofy with the first gear thing. Please help me!!!! This is my main source of transportation, and I need to know if it's worth fixing and how much it might cost me.

Your tranny is shot. You can still drive it but its not going to last.
The tranny starts working better because the fluid heats up and makes it easier for the fluid to flow throughout the tranny.
Drop the pan and get a putty knife and you will be able to scrape a pound of sludge out of the pan.
Don't bother servicing the tranny because my Brother works at Jiffy lube and we flushed the tranny atleast three times on their machine and it didn't help.
You can get a rebuilt tranny off Ebay for about $800.