Your progress is saved in two places:
- As you work on challenges they're dynamically cached in your web browser's local storage. If for some reason it's cleared .. well we get to place two.
- When you submit a challenge it's stored on freeCodeCamp's servers so you'd simply access it from the map and your progress will be accessible to you again.
Now as for not being able to use your cursor that sounds like a hardware/software issue. Are you having cursor issues on just that specific challenge or all challenges?
This sounds like a few issues have occurred, because of the comments about lost progress. Have you checked your progress directly at https://www.freecodecamp.org/map that should be able to fix any local storage issues. If the progress is still lost according to that page I recommend emailing firstname.lastname@example.org and the issue can get fixed from there.