Glad it worked for you.
Regarding the issue in general, I dont have more than one InDeisgn on my computer, so how can it be running 2? I checked the "Activity Monitor" and it only shows one.
As I said: Again, I suspect it is a function of some other program running. If not two copies of InDesign, then InDesign and some Mystery App. So not necessarily two InDesigns, but some other kind of interaction.
As for your double-crashing, yes, this (unfortunately) makes sense.
It means the crash is related to the document you had open the first time, which was somehow corrupt,
crashing InDesign. Then the next you start ID, it reopens the document from the crash-recovery version, but it turns out that version is corrupt too, so it also causes the crash. The 3rd time, ID gets smart and realizes it had tried to crash-recover the same document (unsuccessfully) and does not try again.
So this is normal behavior for this variety of crash.
I think it's even probably correct behavior.