I don't know what to do

So, I met this guy a few years ago. When we met, he was really depressed and suicidal, and even attempted a few times. I started talking to him so that he would have someone to vent to and someone there for him when he needed it.

Anyway, for about a half of a year to a year, I kind of started ignoring him for a while because I didn't want to talk to him (I was getting more and more depressed and suicidal). Well, when I started talking to him again, he eventually said that he loves me and makes... let's say "bigger", if you know what I mean.

He keeps bringing it up and telling me how I make him feel. I went along with it because I kind of liked him and I didn't want him to feel bad. Now he's really getting into it and asking for pictures or if I want pictures of him. He's bisexual, and I don't really know what I am (I think I'm panromanctic grey-asexual), but I don't how to to tell him to stop.

When I talk to him, I feel really gross and uncomfortable, and when I talk with this girl that I like, it makes me...happy, I guess? I don't know, I like her and not really him.

(P.S.: We only talk online since he lives in Canada)

What do you all think that I should do? (Sorry that this was so long)