It's 100% untrue. Men are beautiful. You are beautiful. Believe in yourself and remember that the most attractive thing in the world is a kind heart and that starts with being kind to yourself.
Don't let the world make you feel ugly, they're just trying to sell you shit.
I re-sew my cuff buttons to fit my wrists better cos it's beyond easy, but with stuff like putting darts in I always feel like I would do it wrong. Having a tailor do it also gives that confidence that a second person (who knows what they're doing) thinks the proportions etc are right. But I 100% agree that getting stuff tailored was like magical witchcraft for making everything look a million times better, and even the cost of getting a professional to do it is pretty low compared to the cost of new clothes.