The “and only” has got problems: your voice is cracking,there,
but that’s not the weird clarinet artifact problem you were trying to fix.
Going to 48kHz seems to have got rid of the clarinet, which was the brief.
There is a DeClicker plugin for Audacity at the bottom of this post that can smooth out voice-crackles.
[ get the DeEsser plugin while you’re there ].