Firstly, hooray for you tackling your first sprint!

We're close to the same height, but different builds/size so I can't make a helpful suggestion of something to try. However, I doubt even the right size 2XU would fit. I'm 36A-B, long torso, very short inseam with some seriously girth to my thighs. How you describe the 2XU suit fitting is exactly how I need it, even size S has a long enough torso and generous enough legs that it feels like a second skin.

If you're really set on a tri-suit, try different brands other than 2XU. Personally I love the ease of the suit over a kit - no potential of wardrobe malfunctions during my races.