I am so sorry that you are given a rough time when applying for work, especially in L&D. I agree with the other posters that if a male doctor and male med students can examine and care for females in L&D, then why shouldn't male nurses be there.
My baby making days are over, but I remember when one of my daughter's delivered her first child, she had a male nurse, which is quite often the case when working in a military environment. I was at her bedside the day this male nurse showed her how to get the baby to latch on to the breast. She didn't mind since she, too, was a soldier at the time. Soldiers are used to being cared for by either gender whereas it may take some doing to become an acceptable practice in the civilian arena of healthcare in L&D.
I hope you'll soon find the kind of nursing job you want. Don't give up. You may have to change cities or states, but I know the perfect job is waiting for you somewhere. Good luck to you!