My stutter is coming back and I don't know what to do?

My stutter is coming back and I don't know what to do? When I was young I had a very bad stutter and it had a terrible affect on my school life which forced me to get home schooled from age 10 on. I always thought I would have to put up with a stutter my whole life. However, around the age of 15 I noticed that it gradually started to become easier to deal with until eventually I had barely any issue with speaking at all. Great, right!? Well, I am now a 31 year old man and over the past couple of months I have noticed my stutter gradually coming back. This terrifies me because I have never heard any stories of stutters returning, especially 16 years after it was "cured". On top of that speaking is a big part of my job as my position revolves around making constant phone calls all day. ​ Is it normal for a stutter to come back after such a long period of time? I'm honestly just a little scared and looking for a bit of advice.