I can remember almost every time I've ever v*d but im pretty sure the actual phobia started when I was 6, after going to a street fair with my family and getting a very horrific sv*, I can distinctly remember that day.
Anyway, I don't know if this has happened to others but I've had times where my emet has barely been a problem, it was very bad between ages 6-10 and then from around 11-16 it was barely there at all, just recently has it gotten very bad again