I agree
Never ride the brakes . You will overheat them! the fact you say they were overheated indicates the problem.
Proper method is use the exhaust brake .. Manually downshift how much depends on how Streep and how fast you are going .. The computer won't llet the transmission go into too low a gear.
Now .. Use stab braking .. Pick the speed you want,as max , say 40 .. Brake firmly until your under 30 -35 then release the brakes totally!!!!! ... When your up to 40 repeat the process hard firm braking and release you shouldn't have the brakes on more than 20 % of the time I would think . Give it a try .. You'll find downhill much more pleasant .