Issues with Lexus ES 300 possibly transmission, I think not

I’ve had many issues with the a 1999 Lexus ES 300 recently.  It all started when the car started to drive funny; when at a constant 60 MPH, the car’s RPMs would be higher than normal, at about 4000 RPM instead of being around 2500 RPM.  This occurred at any speed, even at 30 MPH, [...]