Crosstrek swapped battery terminals

[vailsubieskier]

Over the weekend a buddy was switching out my battery and accidentally crossed the terminals. Horn blew and it sparked and car went DEAD. We swapped out the main fuse which had blown and it started right back up....great! EXCEPT, now all the warning lights are on and it won't shift into gear. I can manually shift it to drive and it drives ok. When I shfit it and drive it now it's slow to go into gear and has a little lag in the throttle. Is this something simple like a fuse or a relay? HELP!
It's a 2015 Crosstrek.