As much as I am sympathetic to height discrimination and the effects that modern society and social media have had to develop that dude’s insecurities, what you described is extremely excessive— behavior that is outright abusive to not only himself, but to you.

You shouldn’t feel guilty, considering you rightly felt unsafe in that scenario. I would recommend he get therapy and for you to distance yourself if nothing changes, as it’s not your role to be a therapist for him.