What can I use for de Quervain's tenosynovitis if I don't have a doctor?

Brace. Go the wal-mart in the pharmacy section where the wrist braces are. Ask a clerk to help you find a "thumb spica" splint/brace. It's like a carpal tunnel wrist brace, but it also holds the thumb. Try this for 2 months. If that doesn't do it, then you'll need more serious help.