P = I * A
Typically 10 or 20 AMP circuits draw :
10 * 120 = 1200 W
20 * 120 = 2400 W
Watts of power.
So, 600W is a lot on one circuit, (25% to 50%) of total output.
That in of itself will produce a significant amount of heat.
As @MT_Head says, you need to decrease your draw, and that is only going to be accomplished by switching out the bulbs to a more efficient bulb.
It will be more expensive. but that is the cost of efficiency.