Brakes have too much pressure?

When I start driving I have normal pressure and normal pedal travel. 20 min later I have half the pedal travel and twice the pressure. Then no travel, rock hard brake pressure and the car is lagged by the brake system. I changed pads, greased the caliper pistons, did, had the fluid flushed professionally. This has happened before AND after the flush. It is BOTH front calipers binding on my 2006 chevy trailblazer. Help please, need to get to work in the morning. I am tech inclined DIY with the proper info. Thank you SO much.