I hit the bad luck with the electric system, after installing aftermarket headunit

I have a 2012 Civic Ex Coupe. Bought and made sure the new headunit was compatible n' all. After installing most electronics stopped working and had some weird quirks. Imid, odb 2, lock/unlock button, headunit, and key fob are all dead. And the rev display is showing the wrong revs (2000rpm) is the lowest the needle will sit even if the engine is off.

I did a hard battery reset several times, put the original radio back in and reset, checked every fuse possible. To no avail, I'm about to take it in to a shop but I'm hoping I'm just missing something I need to do.