Don't be so hard on yourself. The more you think "wanting" other men is such a big taboo the more you will want it. I was a lot like you for all of my life. Finally, I met someone who I literally can tell anything too. If I have feelings for someone else, I tell him...He can too. We've been together for 3 years and it takes work but it's so worth it not to have all that guilt. Good Luck!