Characters should be on your PC.
Mine are here
C:\Users\'yournamehere'\AppData\LocalLow\IronGate\Valheim

If it isn't loading it may be corrupt. Who knows. In the character file you should find your character and the previous character save with an .old extension on it. Backup both of those and then in your character folder you can remove the .old extension to make that your current character save.

Otherwise???? Dunno.