2002 Trailblazer reving to high when accelerating

I have a 2002 chevy trailblazer LTZ. It has roughly 60,000 miles on it and has been running great till now. When I got in the car the other morning, and left for work, when I pushed on the accelerator, the car revs to 2,000 to 2,500 rpm's just to get from 1st to 2nd gear. It revs so high just accelerating that I worry and back off the gas pedal. It will shift into gear, but it revs so high. Then the service engine light soon came on and it is going through half a tank of gas in 70 miles. Something is wrong. Checked the transmission fluid and that is good and full, so is oil and filter and replaced the air filter. Any suggestions on what it may be and why? It's sitting parked in my driveway till I can figure out what's wrong and go from there.
Thanks to all reading this and for any help anyone may have.