Thanks for the interesting background there, Confused Female.
There’s probably a million and one things going on in his head.
Without question though, the guy is growing up as far as communicating goes, from the historical recount you describe. Guys are certainly reclusive when it comes to expression of emotion, typically.
I wonder whether he was actually ‘fishing’ around in seeing if you had any emotional interest in him, given he wanted to introduce you to someone that is exceptionally close to him – his mother. That’s one possible signal. And it might explain why he’s distant now, thinking that you aren’t interested in a relationship of sorts.
Have you ever considered a relationship with this guy?