95Mudder

Alright so i started to have a problem with my 95 F150 351w (has 109k miles on it) with the E4OD transmission yesterday. It took more rpms to get it into drive and when at a stop it was not wanting to move under its own power. Today i had put some shutter fluid in it and it seemed better but not completely unsolved, while i was goin up a steep hill i had completely lost drive but had only reverse and park left, what would cause me to completely lose drive?