What a violation. Of a "patient" also, right? I guess your HP has his reasons for wanting you to have that little bit of information. I like that you are tucking it away for later while you keep your focus on your upcoming conference (I call that compartmentalizing) and I hope you have a great time at the conference! That is what was firing you up before this news. Allow yourself to recapture that enthusiasm and completely enjoy yourself. The other stuff is just stuff, and can wait.
And sometimes it is enough that YOU know. You don't always have to share that news with anyone else, particularly your ex. I know a few things about my ex now that I didn't know before, and I haven't felt the need to share them with him or my kids. I do have a good friend I confide in; how about you? Is there someone else you can vent this to besides the ex, just to get it out of your system?