I don't think that catfishing is unlike actors living as a character when they try to prepare for a role; the big difference is that the actors are not behind a computer screen. I think that there becomes this blur between reality and fantasy.
Didn't the catfish SAY he had fallen in love with Manti? I don't think there is any further question about that fact. When Dr. Phil asked him if he was gay, I do believe he said "Yeah, maybe." I think he's still learning who he really is. I think he's been taught, from somewhere, that being gay is an illness from which one can recover. I think it's sad. I do not think he meant to be malicious; he just got "caught up" and truly didn't know how to stop....nor could Manti find a graceful way out of this looniness.
One thing is for sure, though.....this is a total mess. If I were him, I think I would be afraid for my physical safety. It's just sad. I could also see him hurting himself.