No one cares about your 'secrets' as much as you think. They're only potentially valuable if you're doing unpatented research or they can tie them back to you as an individual. The rest is paranoia.
Having said that, I'm paranoid too. But if I wasn't they'd have got me by now.
step back for a bit. some people actually work with sensitive documents as part of their JOB. Like accountants, lawyers, people in medical industry, etc.
Sending a document with a social security number to OpenAI is just a dumb idea. As an example.