stutter has gotten worse recently and don't know what to do

stutter has gotten worse recently and don't know what to do I've always had a stutter, it was most bad when I was little when I was older I still had it but it wasn't as bad, now it's gotten worse, now when I get stuck with words I have to clench my hands or lightly hit my leg to get my words out, it hasn't been this bad before and I don't now what's caused it or what to do, I work in retail so it's a problem.