<human>: Can you condense the text into three sentences or less?

I met this girl a few months ago during a meet-up for people with social anxiety/shyness. I really don't know a whole lot about her so I might be spitballing a bit here. Bottom line is she sent me an email one day asking me if I'd like to do something with her sometime. I interpreted this as merely a friendly invitation to hang out but I think she may have meant something more. I didn't reply. I am not very good at this sort of thing and to be honest was quite frightened by her invitation. This probably sounds stupid but it is how I often feel when someone tries to become friendly with me. I am not interested in her romantically and don't feel bad about not meeting with her. What I feel terrible about however is that fact that I said nothing. Since I know that we both suffer from the same kind of anxiety, I have some idea of what effect this might have had on her. I am fairly certain that I have upset her since I made the mistake of reading some of her poetry on her site in which there are references to somebody "never replying". I'm not going to link anything but suffice it to say that this poetry does not paint a happy picture. I need to do something without giving her the impression that I am interested in her beyond being friends. It is worth me noting that I have met her at other meets since I received her email but have not spoken to her much at these events. She is hard to read/I am not good at reading her so this hasn't helped me very much. Any advice would be much appreciated. This whole thing is causing me a lot of guilt.
<bot>: I failed to reply to an emotionally unstable girl's email out of fear and have no idea what to do about it.