Lightroom not responding, it won't quit, force quit...just freezes

so I had to restart computer

If you did this a few times, I highly recommend you run disk utility on your hard disk while booted in recovery mode. These lock ups and reboots tend to leave orphaned files and directory structure damage on your hard disk. You should restart the computer and hold down the command and R keys simultaneously until the apple logo appears. You'll get a screen where you can select disk utility. Select your internal hard disk and run "repair disk" on it. It is not unlikely that you'll find a few problems that you should let the disk utility repair. If the computer tells you it can't repair the damage to your disk (which it sounds you might have), you should reboot in single user mode and run "fsck -fy" from the command line. It's described here: Resolve startup issues and perform disk maintenance with Disk Utility and fsck - Apple Support and contrary to apple's info fsck fixes more problems than Disk Utility.