Sports bras forever, or is there another way?

My guess is that you are wearing the wrong size bra if you feel not supported enough...go and get fitted in a few places and take the average. Id say, if you think your a 38 C try a 36 D and see if you feel more supported. Its not the straps on your shoulders that support , its actually the band that goes around your ribcage that's supposed to do most of the work and if that measurement is not snug enough you wont be properly supported. If you can fit more than 2 fingers inside the band then its too big. I thought I was 36 B, I got measured and turns out im actually a 32 D, huge difference, I look thinner now! Lol:)