Adad,
I reject you label of "stupid", you have a very serious distraction.
Now, you did the series of the bank correctly but got the ground on the wrong end. Correct?
Have you checked to see if the installed bank is still good? I suspect it is...
If there is a house bank disconnect (aka salesman switch), they are polarity sensitive. If you can find it, check voltage there again.
On a side note. Most of the 12V devices have protective diodes and fuses, so even if those blew, there is little change of major damage. Batteries get hooked backwards with regularity.
I wish you peace.
Matt