Hello and Welcome to FixYa!
Answer to your first query, can your sms's be saved, NO they can't if you are facing a corrupt message, it means that you were saving the texts on your phone and the phone memory is corrupted, as well as your firmware, to get your phone back to work, you need to update your firmware ASAP, to do an update you need the SE Update utility, you can download it
from here for free, all you should have is the USB Data Cable.
After downloading, install and run the application, your phone should be 50% charged and the PC should have an active internet connection as the application will automatically search the firmware from web and will install it to your phone, I hope you will do it yourself.
If you are still having issues, do tel me. I'm here to help.
Concerned, Nooh.