1999 regal

while driving or going up hills my tachometer drops to about 1000-1100 rpm and my car will not pick up the speed-i have to ease off the gas a little to pick up speed-what seem to be the problem?gs 138000 miles

Have the Torque Convertor Control Solenoid checked by a tranny shop. It sounds like the solenoid is sticking and not allowing the convertor to unlock properly causing you to have to let off the gas to get it to disengage.