Are you sure you checked ALL the fuses? There are some large main fuses in the underhood box that don't look like regular fuses, they are square and look a bit like relays. You may have blown one or more of those.

 

blown alternator?

 

Yes it's certainly possible the ECU was damaged. However that wouldn't account for why the engine won't even crank, that is a basic electrical issue that has nothing to do with the ECU. Chances are that if you can get the car to crank it will probably start.
Did you check the fuses by eye or with a meter? You can't always tell by looking, they should be tested electrically.

 

check power, see if its at the starter if not, trace it back to the battery and find out what the last place you have power is.

Better yet, try a new battery. I have seen batteries that show power but are really dead. Small amp draws will still work but large amp draw gives you nothing. Thats my best guess, battery got fried

 

i was working on my friends crx today and did the same thing. checked the fuses and his battery fuse was out. replaced it and everything was back to normal.

 

Check the service manual as well. There maybe several fusible-links in the main wire harness. These are thin wires that act like fuses and may burn out under an extreme condition such as connecting the battery wrong.

I know many aftermarket electronics are equipped with a reverse connection protection. Typically this is a small diode near the power terminals in the device and this will burn out when connected backwards. This is an inexpensive way to protect 12v electronics although it is a hassle to repair it is far cheaper then a new device i.e.... amplifier or radio. Not sure about the factory electronics though.

You may have also burned out the starter when this happened and that would explain why you get nothing when trying to start the car.

Break out the volt meter and start checking the fuse boxes. I have come across many fuses that look good in appearance but are open when tested with a meter.