Pain and swelling

Omg y'all. Yesterday I was in bed and my nipples felt weird inside of my sports bra. Mind you my sports bra is an XL and before this new revelation fit perfectly. Sure there was cleavage but at least I didn't have to worry about a nip slip. Anyways sorry for the image, but I touched my nipple and it was so painful and it was like that only yesterday but I'd been getting pings of pain for a week and a half. But yesterday was awful. But I went to sleep at 8. That is the earliest I've ever gone to sleep. And I'm almost 3 weeks. But today I just think they're swollen. To be honest idk what's going on. I looked up so much, but I'm not prepared. And my back aches. And my friends are like your stomach is starting to swell and it kinda makes me think I'm fat. Sorry this is just a little rant. Don't mean to bother. Just want to know.