94 accord ex 4 cylinder was having heating problems. After check up, mechanic confirmed it was a bad headgasket. After replacing headgasket car doesn't over heat.

However, when car was over heating, if I could keep the rpms above 800, the engine would cool off. Originally we thought it was the water pump, but problems remained after replacing water pump. I started to notice that when ac was on, the idle rpms would drop from 700+ to under 500. Logically, I think this is the bigger issue that caused overheating in the first place.

How do I clean or adjust the condensor or other ac components so it doesn't take so much energy from the idling engine?

I tried draining some freon, or whatever its called now, and the idle improved but ac is no longer cold. I'd like to use ac and not overheat again or have gasket problems in the future.
I'm.m
I changed headgasket myself, so I would like to fix this myself also.