Get Nexus 7 tablet out of reboot loop? Nexus 7 tablet running Android, everything up to date a few months ago.

I was trying to cut down on those annoying auto-updates and all those extraneous apps I never use, and apparently did something stupid.  I disabled (may not be the exact name for the button) a few apps that I have no interest in, never use, and didn't think the OS needed.

Apparently I was wrong about the OS needing at least one of them.  I shut down the machine completely, and did a reboot.  After a few minutes, the OS comes up, and says it's "optimizing" app xx out of yy.  After it gets thru that, the tablet immediately reboots and starts this process all over again.  There seems to be no opportunity for user intervention anywhere there, other than shutting it off completely.  YY can be different on successive reboots.

Is there some way to recover and make the tablet usable again?  Did I irreversibly brick it?  Help!

Added

Was usb debugging enabled in the device? Or, do you have a custom recovery installed or bootloader unlocked? You would have to factory reset the phone if the answer is "no" for all of my questions

Yes, USB debugging was enabled on this tablet (it's not a phone) a long time ago.  However, if I remember right, a factory reset was performed since then.

I don't know what a "custom recovery" nor a "unlocked bootloader" is, so I'll assume I have neither of those.  Yes, I would love to factory reset the tablet.  It won't come up to the point where there are menus and I can do that though, hence the question here.
Apparently, you can enable apps using adb: Enable and disable system apps via ADB

Maybe you can quickly do this while the phone is still booting. (I don't know how soon adb is loaded.) Maybe it works through the newest versions of twrp, which support adb!

Good luck!