Turning emotions on/off

I have heard recently that people with Asperger’s have the ability to turn emotions on and off in a sense my whole life I have been miserable not being able to regulate my emotions and I feel the reason I never was able to develop this skill was because I was always told that I need to find a way to deal with it and not react 

if anyone could help me to be able to teach my self this skill to do it at will to shutdown in a way to help with my emotional regulation and impulse reactions that would be the best thing anyone could give me I have been struggling with my Asperger’s for so long and have only been able to do it accidentally once it was the biggest help but I would like the ability to know how to do it when ever I need to make going through life easier 

any help or advice on how to teach myself this would go further than you would know