Actually it could be that you need a new disk. The timing of after updates to Debian could be coincidence possibly induced by lots of writing to the / filesystem. I suggest before doing anything else to do
Code:
smartctl -t long /dev/sdX
to find out if the disk is failing. If it is, you'll need to try further to recover any important personal data that isn't already backed up, then install on a new disk. Even if it checks out OK it may be too late to recover the whole filesystem and need to reformat and reinstall.
Have you tried booting from a prior kernel instead of the latest?