iCloud deleted my Outlook contacts after install

I downloaded iCloud for Windows this morning and when I was done and opened Outlook, my contacts were gone. I'm on Windows 10 on a device less than a year old. There was a second iCloud menu in the Contacts folder, and when I clicked on it, SOME of my contacts were there but not all of them. I suppose I can deal with iCloud taking over my contacts (WITHOUT TELLING ME THE CONSEQUENCE), but I can't deal with an incomplete sync (or whatever happened). How do I get my full set of contacts back please? One more twist, the contacts that are missing are still available on my iPhone, which is helpful, but I wonder if they will go missing as well. Please HELP!