Hey, I think this is a really big issue. I've found that a support system is incredibly helpful, even if it isn't from your own family. The way I would deal with it is I would find a safe place where you can get support. This can be from close friends, or a speech therapist. I found it in NSA self help groups and made friends at the NSA conference. I also listen to the stuttertalk podcast when I need to get away from ignorance. You first need to learn not to beat yourself up and change the way you view yourself and your stutter. This is where I think self help comes in. Once you spend time around other people who stutter, see how they view stuttering, how they are ok with it, get more educated on what is going on and how much we can achieve while stuttering, you'll be in a much better position to talk about this with your family if you so choose. I can imagine their negative expressions are projections of their own feelings and insecurities about your stutter and unfortunately you end up on the receiving end of it. But assuming they want the best for you, it can be explained how their behavior is only hurting.