I am having the following problem. No one seems to have any idea what could be causing this.
When driving at least 50 mph (usually), when I speed up to change lanes, etc., the gas pedal becomes difficult to press down. This happens between 1500 and 2500 RPM. The engine revs up to switch to the next gear, but instead of switching gears and dropping RPMs, the RPMs stay at the threshold right before the car changes gears, WILL NOT change gears and resists my attempts at accelerating. If I try to force the gas pedal, the car literally jumps off the ground. (I thought it was just an illusion until my car actually bounced over to the left in my lane....) If I force the pedal, it jumps repeatedly, eventually switches gear, then the RPMs go up to like 3500, then back down. If I ease off the gas completely and then accelerate, it will generally shift gears rather smoothly. Have you ever heard of this happening before?? Is this something I should have taken care of immediately? It would seem as though it is.

MANY thanks in advance to anyone who can help.
-Beth-
P.S. As a rule, I usually don't drive my car sadistically. I dont abuse the engine/transmission.