I have PTSD. I have a guy I've been cancelling on for quite some time. (If I told you how long, you'd be a bit shocked that he puts up with it.) Anyway, it could be PTSD as some of us are quite avoidant at times when it comes to relationships. This avoidant stuff is quite confusing for outsiders. We feel comfortable with people up to a point, but then getting too close can make the anxiety set in. To non-PTSD people, relationships are generally a good thing. To PTSD people, relationships bring SO much stress to our lives that we tend to avoid them. (And its more than normal relationship jitters, SOOOO much more.)

Long/short, he was likely in to you but when it came time to go on a date, that was outside of his comfort zone, his anxiety set in, and he backed out....repeatedly.