Being a man and wanted to get pegged are not mutually exclusive. You can be plenty manly and still have a woman give it to you. To be honest, a pro dom probably isn't a bad way to go since she'll know what she's doing. Men do need to be a little careful since you can damage the prostate.

So in short. You're desires don't make you any less manly. Many men have the same desire. (Heck, there was a weird rush here in my home town when a bunch of guys found a pro dom who would do pegging.) In my opinion, you won't mess up your mind, won't turn into a woman and who knows, you might actually find a new confidence and will feel a little happier.