Did you try a 32A? It sounds like from your chest size you need a 32, then it's a matter of matching cup size as best as you can if you even need a bra.

When I was getting mine I got measured and really guys measure better then girls do. But get measured and they will find one for you.

When I started changing cup sizes, I had the same problem with ill-fitted bras so I looked up how to find the right size. So, they say to measure above your bust to find your band size and round it to the nearest even number but I think it's stupid because that really isn't where the band goes so I measure right under. Then measure the fullest part of your bust. Then, subtract your band size from the cup size and if the difference is 0, you're AA, if the difference is 1, you're A, etc. I think you should try a 34AA though, maybe that will fit.