As a woman who has had tons of trouble with bras, I highly recommend abrathatfits.org. It has been a game changer. The subreddit has some great resources as well (not sure if that’s changed since the protests though). But anyways, the majority of women are wearing the wrong size bra and don’t realize it. I went from a DD to an H. I can wear my bra all day and barely notice it. If you’re breastfeeding I suggest measuring when you’re half full. That’s what I did when I was breastfeeding and got the best results.