Transmission issues

My automatic tranni just may have tanked (1997 4x4 4.6L) was driving home from coaching at the park and at a stop light, the truck would not move forward in any forward gear (moves a little, very slow). Works great in reverse. Fluid level is good. If I rev it in forward gear it will occasionally catch and take off and work fine until you slow down and it losses connection. Any similar experience? New tranni or does it sould like something less severe?