Holy shit, anon. Are you me? I like America humiliation in general, but fuck me I've gotten off to HobbyHobby's chubby!America doujins for the very thing you've described. >>2562251
I've managed to scrape up a few good things from within the bowels of Pixiv. Otherwise, most art of weight-centered America art is usually to depict him as fat stereotype character, or deviant art-tier fetish stuff.