I posted this question explaining what happened after I tried to create a new swap partition on a Win/Ubuntu dual-boot machine. I have since created a live-boot USB and installed Boot-Repair. I had it "recommend repairs", after which it tried repairing the wubi filesystems, which as far as I'm aware was not necessary. I'm not sure where to go from here; I don't care very much about backing up my files, I just want to be able to boot the machine.
In the Advanced Options
the "Repair Windows boot files" box is uncheckable
both GRUB tabs are unclickable (I do have GRUB installed)
Here is my Pastebinit with the details from the Boot-Repair. Please be as explicit as possible, as I am proving to be disproportionately bad at this type of task. Thank you!
P.S. I keep seeing:
cryptsetup: WARNING: failed to detect canonical device of overlayfs cryptsetup: WARNING: could not determine root device from /etc/fstab