Using Windows 10, and it turns out I overwrote my current Office 365 PST file with one that was two years old (I have no automated backups, just do them manually). I copied and pasted the old one over the current one by mistake instead of the other way round. I tried going into the properties of the pst file and restoring an old version but no old version was there, and also tried the same with the parent folder but no luck. I then tried hitting CTRL-Z to see if it might reverse the overwrite and all it did was empty the folder of the PST file and not put the old one back.
Am I totally screwed, or is there a way to somehow recover the most current pst file???
Any help very much appreciated,