Don't know exactly what or how, but I accidentally deleted all the vst tracks from my project, only my mixed audio was there, and it had already been saved--it had also previously been autosaved in that same state. I didn't think there would be a way to get my work back without re-recording and re-editing everything all over again. I was not ready to do that after a couple of long days of work on this project. But I looked in my file manager (windows explorer) in the project file, and found several of these files located there, with the type of file being this:
Free Way.cwp.~2018-08-06-13-27-19-857
There were a few of these, and one was time stamped as being modified about an hour before my last saved version (the one with no vst data anymore). Since I couldn't open it up by clicking on it, I simply renamed the file, by deleting the tilde, and the date and time stuff, renamed it "Free Way previous version.cwp" THIS I was able to open, and lo and behold all my work was there, the most recent edits I had made, and nothing was deleted. So I could now Save As and overwrite the damaged file's name. All is well now.
So hopefully no one else will suffer this problem in the future--if you want to find a previous version older than your last autosaved version, open the file folder (assuming you use per-project audio files) in Windows Explorer, you will find those funny lookiing file names there, and you can rename and put a .cwt extension on it, it will then open in Cakewalk and you can go on with your life without a heart attack.
Whew! Gotta be more careful when I'm working, however. Senior moment, I guess.