As you can probably deduct from the title - I've made a rookie mistake..
After accidentally locking my entire designer up by starting preview mode before finishing my script, I force-closed it via task-manager.
Expecting to have lost my changes since the last time I saved, it turns out I lost all changes since the last time I closed the designer.
When opening back up again, I got notified 'another user' was working in the same project and saving could result in conflict. I started to take stock of what exactly I hadn't saved since earlier this afternoon, but discoverd all my changes of the past days (since I've opened the designer, essentially) had been lost instead.
As the designer seems to think 'another user' is still working in the project, is there a way for me to retrieve what was lost, do I wait until the session times out, or am I just going to have to redo the last 3 days' worth of work?