Hmm...this all sounds so strange, as I scrolled up to see what your measurements are, and you are 29 1/2 inches under the bust, which is strange, I'm 29 inches under the bust if I breath in, if I exhale all the air out, I'm 27 1/2 to 28 inches under the bust, and I had no problems going to the large, and can fit both XL's on my chest after prepumping with the L's. So strange that I can fit them and you can't. Also Kultzu fit them, and I believe she's even tinier! I never tried the blue tack method, when I first got my pump I got the mediums and the soft cup rings, I tried them but didn't like them, I prefer pumping without them, so I don't use any type of padding. Have you looked online for the blue tack? Or have you tried the yoga mat method?