Most men have some curve to their penises. Are you unusually large? Are you sure it is the curvature that is hurting these women? Perhaps you should insert your penis in such a way that it is easier for them to take, head directly in first and then ease the curve into it. Which way does it curve?
Although a certain degree of curvature is normal, an excessive curve might be Peyronie's Disease. The only correction I know of is surgical.
I have the same thing and ask the same question all the time. No answers... :(