I'm about the same size (5'7", 130 lbs). It really does just take time. You have to have a little patience with a Brooks. I've put about 800-900 miles on mine, and it feels really good right now. Expect to spend at least a few weeks on the saddle before it starts to feel right (depending on how much you ride). Proofride it too. Like someone said above, a Brooks is supposed to provide support for your ass, not a hammock for it to swing in.