Macbook Pro is terribly slow, crashes, no startup volume, and so on.

Hi all,

Yesterday my Macbook Pro (2010) was really - really slow (happens more often, but yesterday was terrible). So slow that I couldn't open/close any applications. I shutdown my Macbook using the on/off button to restart. Rebooting (SLOW) opened the utilities screen, not OSX Mountain Lion (with all latest updates installed). Utilities couldn't find a startup volume. I tried disk repair, estimated time left was 8 hours, but it stopped after 2 hours "Cannot repair disk, format & recover from a backup". So I formatted my disk and recovered from a Time Machine backup (too bad my last backup was 3 months ago).

Now my Mac is still terribly slow and quite unstable. Yes, I have access to my files now, but a regular task that normally takes 5 minutes (like burning a DVD) now takes about 5 hours. Any idea what is wrong? I already made an appointment with a Genius, but I'm not sure whether he can fix this...

Hope you can give some suggestions / tips to fix this, thanks!