The guy I was meant to go on a date with cancelled because he was too anxious

Sadly, people who suffer from anxiety do this; they stop themselves from carrying out some activities, even if they want to do them. Their anxiety is triggered by several things: fear of the unknown, self-doubt, lack of trust and an unsecured environment
( away from their home, something they can't control). I think he deserves credit for confessing the truth and most likely does indeed want to meet you but is just too anxious to do so. While it's nice of you to want to help him, he may need instead the assistance of a qualified psychotherapist. I would suggest you allow him time to seek help and heal from it. Although it may or may not work, depending on his willingness and capacity to overcome his anxieties, and also depending on how good his therapist is. Depending on your feelings for him and your sense of self-preservation, you'll have to decide for yourself whether to wait for him or move on. Good luck.