Hmmm, only one save. I'm guessing that's a new save too.
I'm not a RenPy expert, but I've never seen something like that happen before. I suppose that a developer could kill old saves using some code jujitsu, but no one else has reported that issue with the .11 patch, just the 'hidden saves' and 'corrupted saves' at the very end of Day 10.
Any chance you have a DMD 0.9 folder lying around somewhere? You could look there for some older saves if you had it still. You'd have to replay day 10, but that's better than starting at day 1.
Also, the ctrl key can be a godsend when skipping through dialogue, and the pageup key can back you up a few lines to read the relevant dialogue when an unfamiliar dialogue choice comes up, if fast skipping is enabled of course. Not ideal, but it'll get you through day 1-10 a bit faster.
You might also be able to grab one or more of the saves uploaded here as a starting point, but there are a lot of pages in this thread so it may take a bit to spot one.
Sorry about not being able to help more here!