Can't stop hating my best friend

Hi, I need some advice regarding a problem that I can't stop dwelling on. Years ago I was seeing a girl (my first serious girlfriend), and after a couple of years we broke up. We got back together on and off, but it was never the same. A few weeks after we split I bumped into her in a nightclub, and I'm ashamed to say that I told her to go away as I was in a really foul mood and in all likelihood still hurting. Later on I found her with my best friend. He came over the next day and explained what had happened and that it was only a drunken incident. A week later, I was out with my friend and I asked what were his plans for the next day, he stated that he was seeing her on that day. I have never felt so shocked in all my life, apparently I turned white and looked like I was about to vomit. Anyway, he spent the night with her and told me days later that they'd slept together. I was absolutely heartbroken and furious. This happened years ago, and since then I've married and had kids. Me and my 'friend' still occassionally meet up, but everytime we do, all I can think about is that one night, even though it was years ago. I try to ignore him but he lives in the same small town and his parents live next to mine, so everytime I see him or even his parents, it all comes flooding back. I've tried to block it out of my mind but can't and despite the years going by, my feelings of hatred and betrayal are growing instead of diminishing. Has anybody been through this before and can offer some advice.

i,ve been there.my girlfriend in which i had a child by was staying with my parents and going with my best friend.so the feeling will go away with time.but maybe you can tell him how you fill..other then that it,s there