I agree it may not be a catastrophic failure even if you are describing one to the T. Youre describing transmission slipping, where basically the Engine RPMs dont match your acceleration--like its overrevving and not moving as such. Try to have a competent ford tech or independent mechanic flash the trans Control Module or P(powertrain)CM. If it ends up being the transmission, then id try some stop-slip by Lucas Oil or something of the sort. Nothing to lose and its actually helped me before.