Three really simple things I would start with...
1. Look at the flat plate in the bottom of the sub frame with the large hole stamped in it. Obviously it should be flat, if it is wrinkled or warped something is bent.
2. Pull it up to your garage wall, square it up and see if both ski tips are touching the wall.
3. Pull off your side panels and run a tape measure from your jack shaft to your ski bolt on each side, obviously they should be real close. If not your the newest member of the bent sub frame club congratulations...not!
Good luck, and glad your alright after your "mishap"