Radiant I have experienced a similar reaction from a family member - similar response to your mother. It didn't affect me as much as a counsellor who I saw in my late teens who pretty much said the same thing. That hurt me the most, as they were supposed to be a professional. It had a lot of impact on my already poor self-esteem.
It has affected me as it has made be a lot more cautious about opening up to people. I have tried therapy again since but I just can't do it. I don't think it's right for me, and that's okay. I have found this place a lot more beneficial.
All I can really tell you is keep trying. I sometimes have to actually say SHUT UP to that voice that is telling me that no one wants to hear what I have to say, or that I'm annoying, stupid etc etc. Find what works for you. I can be pretty much completely open on this site, so that's what works for me. Other people's dismissal of what you have or are going through is a reflection of their own shortcomings, not your own.