Stuttering when standing in the queue

Stuttering when standing in the queue In my childhood I never stuttered or stammered, but when I was 7 or 8 years old I saw my aunt commit suicide by firing. It all started and from the age of 8 to 17 I stuttered so badly. But now I am 30 and my stuttering has decreased, and I stutter only 20% and 80% cured by itself and I don't stutter all the time, but 90% of the time is stutter when someone on the counter asks me my mobile number. Number starts with 7, and starts with "SAA" sound, and It's hard for me to speak words starting with S, R, T. If someone has the number problem your help will be appreciated.