When I run the A/C the engine loses a lot of power. When A/C off runs good.

What is your question?

The A/C causes a substantial loss of engine power. The only thing I can do is turn the A/C off and turn the engine off for awhile. Then when I restart the engine without the A/C being on the car runs fine.

What makes this problem better or worse?

Turning off the A/C and allowing engine to rest for awhile.