100% have the same problem. I have a really hard time carrying a conversation with family and friends. My family puts me on edge and makes me blank out just as pad as a perfect stranger. I also never answer more then a few words, and rarely elaborate on anything. I think a common symptom of SA is mind blanking when prompted with an anxious situation. Hence why I write down personal information if I have to make a call. I will forget my phone number, social security etc if asked.
I also find I don't stand up for myself around my family very well either. They come down on me for not doing this, or doing that and I just take it. When many of the times I really should speak up. I really thought all this would fade with age, but it hasn't.