Stutter coming back & Flaring up when I hear others stutter.

Stutter coming back & Flaring up when I hear others stutter. I had a serious stutter till I was 8 which abruptly stopped when I became mute. That ended three years ago and am now speaking fluently, yay! Except it’s coming back with a vengeance. I know it’s probably because of the amount of stress I’m going through but I at least want to try to control it. Do you guys have any tips on how to get rid of it or even manage it? Also if I hear someone else stutter, mine comes back full force for a day or so and I feel horrible, like I’m mocking them. Why in the world does that happen? Thank you!