cruise on and engine brake off driving me crazy

[medseg2003]

hello every one
i have 2013 cascadia isx2250. yesterday i was driving normally like every day.suddenly cruise kick in by it self and start increasing my speed without touching it . i try to turn it off it won't it stuck on, i push clutch to deactivated it won't the icon still appear on the dashboard., the only way i can turn it off is to push the brake pedal and turn it off manually but after 10 seconds it kicks back on again and keep increasing speed. i notice also that when the cruise kick in the engine brake is not working i try to turn it on by pressing the switch but it 's not responding at all.
i did also try to turn the power off from the batteries and turn it back on see if it help but no luck still same problem.
i drove like that for 100 miles to make it truck stop. just 2 miles before truck stop exit i succeed to turn it off manually and also the engine brake switch is working normally
any one face this before please help thx alot