Tight bra / chest pain ?

My breasts are kinda on the saggy side from pregnancy and breast feeding anyways so I now wear normal lightweight bras I’m comfortable wearing it all day but as soon as I get home and take off my bra, my breasts feel kinda sore. I also keep getting a shocking pain in my chest idk if it’s related or some other issue. I used to experience it before but once In a blue moon now I experience it everyday a few times a day. I keep feeling a need to take deep breaths or yawn. And it just feels awkward in my chest and then my back would feel like it needs to crack or something. I toss and turn all night. I do have anxiety attacks.