Car not running right after main fuse replacement

Hey guys, I have a little problem here that hopefully you guys can shed some light on. A couple days ago after I got home from driving my 7g 1995 Galant Sports GT TT. I had to help a mate start his truck so being a good go I let him use my battery. Now this where it get interesting once he finished with my battery he decided to put it back in my car and then bang he put the terminals on the wrong way. So yea had to buy a new 100a main fuse. Installed the main fuse, turn the key and yes the car started. But now is running rough as guts with bad acceleration cannot even feel the twin turbos spooling, plus on top of it the rev counter stopped working. Any ideas? Everything is stock and was working perfectly before that little main fuse mishap.