Have you tried softening it? If not, put it in a plastic bag after covering the top and bottom surface liberally with neats foot oil. Soak it for a day or two. Wipe dry and ride. I never touch the tensioning bolt, I have only ruined the saddle by doing so. Read Sheldon Browns web site on care of Brooks saddles and breaking them in. The B-17N is fairly narrow at 151 mm. For me this is too narrow and I had to sell them and go with the 170 mm wide models. The narrow models, swift, swallow and b-17n end up feeling like the symptoms you describe. I have found any tilt ends up being uncomfortable and go level. As i have posted earlier in other threads, for me , a wide hipped cyclist, the brooks is the only comfortable saddle I have ever ridden. I have never needed more than 200 miles to break one in. If it is still uncomfortable at that point than I have found I needed a different model which has always meant wider.