First of all, well done on telling her. I know that it could not have been easy.

I would agree with liveforfish that she probably needs some time to adjust. From what you have said she didn't seem to want to hurt you but also wanted to say something supportive.

If it is still bothering you though in a few days/weeks I would suggest talking about it. Let her know that you understand she was being supportive and are grateful for her trying but also you felt _____. If possible also let her know what you need from her. For example, whether you are comfortable with her asking questions about it to understand more or if you will tell her when you are ready.

A lot of people really want to help and be supportive but aren't sure what to say or how to say it and often end up saying the wrong thing unintentionally or nothing at all. As hard as it is sometimes it is up to us to guide them in what we need so that they can be supportive.