Flashed AOKP JB 4.1.1- Now I'm in Trouble

view story

http://forum.xda-developers.com – I flashed AOKP JB 4.1.1 the other day, started having trouble with google play and other apps force closing. When I attempted to flash back to a different rom I couldn't connected to my computer via usb. Also on some apps it's stating my sd card is not mounted. I'm not too sure what to do now. Can anyone help? (HowTos)