Teenager who acquired a stutter about 6 months ago

Teenager who acquired a stutter about 6 months ago I'm not sure why I've started stuttering. I never stuttered as a child, and my stutter isn't too severe, but i block up while talking with a group of friends or at parties. I have to substitute some words to hide my stutter . Ex. Instead of asking, "Can I sit down?", I ask "Is it okay if I sit down?" so I don't block up on can. Sometimes, my parents pressure me to speak when I'm stuttering, and tell me to slow down, thus worsening the problem.