Best friend revealing your condition to another

Hi, please excuse this long post of mine but I don't know who else to turn to. I am hoping some of you, any of you, can help me. I really need some perspective on something that has just thrown me off balance.

I'm a guy and my closest friend is a guy, we are old college friends. I confided in him 3 years ago about a medical condition I have (MS). The same time I met a friend of his (a girl) who I really liked, and she and I became good friends and have remained good friends ever since.
My friend and this girl started dating recently and broke it off, yet she and I have remained friends.

I found out recently that my friend told her about my medical condition the same time I told him about it (3 yrs ago), which is also the same time I met her. When I asked him how he could go and do something like that, that it was something told to him in CONFIDENCE, he said it just slipped out, and apologized to me. This has really thrown me off balance and I don't know how to deal with this, and it is really affecting me that he breached my confidence on something so sensitive. To add to that, that this is one of the first things she got to know about me. And although we are still good friends today, I can't help but think that our friendship started on the footing of this knowledge.

Does anyone have any perspective on this? I am a very private person, I don't talk about my medicals to anyone (except a very few friends know about the MS). He is not a friend I'd like to lose but now I am having trust issues and it's causing me a lot of anxiety.

The biggest thing going through my mind is he revealed what I told him in confidence.

Thanks, any advice or opinion would be appreciated.

It is quite hurtful when someone exposes you like that; I have had it happen to me about my childhood trauma...I was quite angered initially, but have resolved it by understanding how imperfect we all truly are...it took me a couple of weeks to get to this point (and yes, I spoke to my friend about this and we repaired the relationship) but feel much better not carrying it around...we forgive for ourselves...big hugs, J