2002 Chevy Silverado

Started truck up and it rolled over than died, tried again and it started. I bought a new battery and replaced figuring it was time, especially with the cold weather. The tow/haul light automatically came on and would not go off with the pushing of the button. Turn truck off and light goes off but will not come back on. Now two day later I touch my brakes and the light flickers as well when I change my bright to dims. Just wondering if it could be a computer problem