1998 Chevy S-10 Loss of power

Engine problem
1998 Chevy S-10 4 cyl Wheel Drive Type unknown Automatic 94,000 miles

My 1998 S-10 just recently developed a "jerk" while shifting as if the RPM was running very high before dropping into the next gear. I had the transmission checked and I was told it was in perfect working order. Just today, the check engine light came on and as I was trying to accelerate, the engine revved very high and lost power and would not accelerate.