Bikini top alterations

SOS
Hi all, this group was recommended to me to ask for help!! I bought my swim suits for the summer, but my usual problem is that the actual bands and body sections fit well while the cups for my chest are too small. I can’t size up or it won’t fit my ribs. I hate underwire and have an “uncommon” bra size that restricts my options anyways.

Has anyone altered a bikini in this way before that can offer some recommendations? I’ll answer any clarifying questions! Thank you in advance, I’m desperate 🙏🏻