I loved this. I have been that girl you described so well - not in your particular situation of because my date was disabled, just when I no longer connected and felt uncomfortable about expressing why, sometimes for reasons I didn't even understand myself. The point is not to make you feel worse, but to thank you for beautifully describing the feeling. I have also been on the other side of it and it sucks.
It is unfortunate that you have been treated in this way, but I think it is more a reflection of the other person than you. Clearly, she was self-conscious about how she would be perceived by others rather than following her heart. I've been there too and thankfully grew out of it as my confidence increased. I am now married to someone who isn't traditionally attractive, but nice and funny and a great partner. That's a reflection of where I've arrived.
I have to say, for me, I was actually once attracted to someone because they were in a wheelchair. I was walking into the mall and he held the door for me. He had one of those magnetic personalities, so much so that I put myself out there after only a brief exchange and asked him if he might want to go out sometime. He told me he had a girlfriend and my heart was broken a little. I saw him as a person, not a person in a wheelchair. I hope this gives you hope that girls like that are out there, just harder to find... Sigh.