There's a lot of factors in how "socially acceptable" fat people are, including how old you are, your country, your gender, if you're gay (definitely a lot of fatphobia in gay communities even in america), your family, etc
I don't know what culture is like in Argentina, but if you're actually an Argentinian man above like 25, chances are no one in public is gonna give af other than the rare dickhead if the obesity rates posted online are to be believed. Comments and looks do really suck, but you will feel so much happier generally when you're in the body that aligns with yourself. And that's to say nothing of the whole fetish and sexual fulfillment aspect of it.
The amount of people who will want to date you will be smaller, it's true, but would you really want to end up with someone who doesn't like you fat and wants you to stay fit? There will be comments, there will be uncomfortable moments, but they'll just be a drop in the pond. Once you're fat, those moments will feel much less anxiety provoking over time. Unless someone in your life is constantly making you feel like shit over it, I don't really see why you wouldn't.
You could die tomorrow as well! I firmly believe in living without regrets.
And finally from a gooning perspective, you're already in too deep it sounds like... one day the dam is gonna break and you wont be able to help yourself anymore. You're GOING to end up fat as fuck one day, why not just make it happen sooner? You clearly want it so bad...