Do your settings reset every time you restart the game or was this just a one time occurrence?
If you open your osu! install folder using the "open osu! folder" button in the options menu, you may be able to find a backup of your settings. The file will be named something like "osu!.<pcname>.cfg.1234567890.bak". If you have one of those files, you can close the game and remove the numbers a .bak from the end to restore your old settings.