NSFW, Does size matter or does trying and being a good guy count?

Ok. I’m an average guy. I’m in good shape. I’m smart and I’m a hard worker. I’m extremely loyal and a bit of a cynical romantic. If I’m in a relationship I give it my best shot. But I aim high on the bar. I mean really attractive women. Getting them is easy but keeping them is hard. Im a nice guy. I hate it when women stereotype all guys as assholes. But when I finally think its going good it ends and she ends up with some asshole. Im beginning to think that its the sex. Again. I’m an average guy. I’m not hung like a fucking horse. But it makes me ask the question if it’ll always be that way. I really want to love somebody beautiful but when they find someone better they leave. Does size matter even when you look good and treat them even better. I need insight to this.