Can anyone offer suggestions/help?

Ka

So I tried sizing myself for a bra and got a 32B. When trying it on, the band was so tight (even on the loosest hook) I could barely get it on. So I went to the other suggestion of a 34A, I've been wearing it, but the band is always digging into me and causing red marks all underneath my boobs, around my side and back, and this is with me wearing it on the loosest hook also, the cups are too big for my breast. I'm at a loss and don't know what else to even try. I can't find anything that would fit, and if I do find something it's always $60+ for 1 bra and I can't afford that. Does anyone have suggestions? I've been trying to put weight on in hopes I can get a little more breast fat but I haven't been too good at eating healthy or eating what I should be.