sounds like your doing good, now unplug your brake lamp switch. It is a simple switch with a 2 wire plug on one end and a push button on the other. It is activated by a flat pad attached to your brake pedal arm. On mine the bracket for the switch broke allowing the push button to pop to the side of the brake pedal and was not shutting off. Had to take it off and weld it.

Unplugging your switch should make the lights go out. Your brake lamp and signal lamps use the same circuits and elements in the bulbs. Turning on your signal lamps opens the circuit from the brake lamp switch and closes the circuit from your flasher unit. this is why your lights are going out on one side when you turn the turn signals on.