I was a 32G before and I'm already up to a 34GG
I have a similar problem to you but I swim 3 times a week. I've already swelled out of my normal swimsuits and I've bought a maternity one from H&M. It's holding me in at the minute but if I get much bigger I'll have no hope.
I'm thinking of looking at tankinis as you can get a larger top and smaller bottoms. For holiday wear I wouldnt be too worried about having cups but if you get a good tankini that should give you support without having to go all the way to a bikini