I’m afraid not. It’s never nice to hear in the moment , but you should always back up work you care about. That’s not to excuse CSIDE - this shouldn’t happen and it’s a bug I’ve known about for a while and not had much luck reproducing/fixing (hard to emulate a power cut!). So I do apologise but I’m afraid I don’t have a solution for you.
I am working on a revision plan to CSIDE to address a number of critical bugs, including this one. In the meantime you might want to checkout New Choicescript extension for VS Code (2.0 now runs games!) as an alternative tool.