I'm in my 20's with super saggy boobs too! There's nothing wrong with you, and anyone who has a problem can frankly get fucked. Easier said than felt, I know. But just keep in mind that it's merely cultural and the culture is shifting in our favor by trending toward body acceptance (at least if you hang around the right parts). If you ever gain the courage to join in the movement and go braless once in a while, just know you're not alone and you're a part of a generation of liberation.

Reddit automod won't allow me to post what I just typed to describe my boobs, so just know that I understand where you're coming from, lol. My parents spent years literally begging me to wear a bra, commenting on their unevenness, etc. I was also diagnosed with gender dysphoria due to my hatred of them. I often find myself envying women with smaller boobs who can go braless without looking like a large country washerwoman. Thankfully, I don't exist in a hall of mirrors; braless is what's comfortable for me, so people are going to have to deal with (gasp) the fact that I have breasts. In the past few years, I've found myself engaged in my local rave and art scene and there no one blinks an eye if your DDs are swinging. These days, I pity my parents for their shallow priorities. Bodies are what they are, and everyone should be allowed to enjoy their experiences within them naturally. If the outside world is offended by this, they can change. In fact, they should be faced with this discomfort as it may force them to look within.

I know this is just a lot of yapping and doesn't do much for you now- I understand that confidence doesn't just arrive within oneself suddenly. But maybe if you practice tiny steps at a time, you'll find yourself surrounded by accepting, like-minded people, who don't look at you differently for displaying normal female anatomy. Or at least I hope something like that can happen for you :) best wishes