Indianfox, you have received some good advice. The consensus basically seems to be, ignore and move on.
I realize this is something that has been traumatic to you. One thing you need to realize is that the more something is disputed or talked about, the more valid it seems to others. As difficult as it seems it would be, from my experience, just live your life, be with friends you trust, ignore the rest.
I don't know what age you are but when I was younger, this was more difficult for me to do. Maybe as we get a little older, we begin to realize there are things we can do things about and there are things we can't. Put energy into the positive things going on in your life. An injustice has been done to you by the rumors. This I think we would all agree on. A couple of months down the road and you will look back and wonder why you put so much energy into fighting a battle that needed to just be ignored.
When someone says something to me negative I like to just smile and say, "Consider the source!" That leaves it in their court as to whether to believe what was said or not and you will realize in time, there is nothing you can say or do to change someone's mind. Those who choose to believe the rumor will believe it and those who don't won't. I just don't like seeing you put so much energy into trying to squelch a rumor that will die down sooner if you just move on with you life and let it go. (Please don't misunderstand! I know rumors hurt, we feel violated and I am not down playing that part at all. I still hurt for you realizing how upset you are but my best advice has to be, stop talking about it (except with really close friends if you need to vent about it or sharing here on the site) use your energy for the positive things and people in your life and enjoy each day.
Sometimes people react like animals in that when one is down, others attack harder. That is one reason in an earlier post, I suggested, just walk with your head up and ignore those whispering. In private, I know your heart will hurt but they won't know it and the stronger they see you stand, the less likely, the whispers and laughs, etc. will continue. If they don't see it having an effect on you, they will give up and move on to another subject or person. I'm so sorry people can be so cruel but it is a fact of life. We have to each make a choice to stand proud as to who we are and do what works for us. After all the advice you have received, it comes down to you knowing in your heart what is right for you and do it. As I say, you have gotten some great insights here on the post but ultimately until a person walks in your shoes so to speak, no one would be able to know what will give you peace in your heart. Choose well and know this will pass. Best to you.