why did my tacometer rev up with no power while in drive

What is your question?

I was driving about 70 mph (with cruise control on) and coming to a quick stop when my engine/tacometer revved up all the way to red. The car would barely move forward. There was a slight burning smell that went away, eventually. I turned off the car and let it sit. After about 30 minutes, I started it and drove off fine, but it still feels like it's not as powerful as it should be.