Before doing any of this, back up your current scene collection just in case things go wrong -- try to export your scene collection through the OBS menus, and if that ends up crashing, then go to your scene collections folder and copy/paste everything to a safe place.
C:\Users\<username>\AppData\Roaming\obs-studio\
With everything backed up, open up the .json for your scene collection, and remove the entirety of the problematic scene's markup.
Open up OBS, and cross your fingers.