Ac/ overheating

And also whenever I turn the AC back off it almost instantly goes back down to where the temperature should be

The AC uses engine power which is noticeable when you don't have much to begin with. You may need to service the engine cooling system but you should also check to see if the cooling fans turn on when you turn the AC on.

The AC uses engine power (which makes more engine heat) which is noticeable when you don't have much to begin with. You may need to service the engine cooling system but you should also check to see if the cooling fans turn on when you turn the AC on.