Not sure that I’ve understood everything correctly (my English is still needs improving), but maybe this will be a piece of help for you:
Disk on the disk brakes is placed between two pads. One is movable, and one is not. When you squeeze the lever, the moving pad is pushing the disk to the unmovable, and the friction stops the wheel. This friction is generating a lot of heat, that is why it is normal that disk is warming while you brake.
However, there is also the situation, when unmovable part changes its fixed position, and, depending on where it moves, you may face two results - you cannot brake at all when you completely squeeze the lever or the pad always touches the disc, generating slight noise and heat.
Now you may think of your situation: if it is movable pad - change the position of the fixing bolt on the brake cable. If it is unmovable pad - from the opposite side there is a hole for a hex key - you may adjust the position of the pad. Start from 1 mm from both sides and then adjust based on your feelings on the lever.
Good luck!