Bathing Suit Help! Swimming tomorrow & lacking in the Upper Area! D:?

My friend and I are going to a Public pool tomorrow and lets face it....I'm Flippin' Flat XD I wear a 34B but thats because I have a wide torso. I'm uberrrr Skinny and losing weight isn't the problem. I like my Body and I'm 5'8. And Pale :/ but besides that, the real problem is that I'm Lackin' at the top. My waist is small and I have a Fuller Bottom, Like Tush and Thighs, but Everytime I put on a Suit That seems to be the problem. I have a Triangle/Halter top/Padded/Lavender Color. But I can't run out by tomorrow and get a more flattering suit. And Tips or Suggestions to help fit this? Tighter at the top, Looser, Whattt? Thankyou in advance!(: Love yall!<3