Look, I’m all for DIY, but if you shock your well twice and the smell comes back like a bad ex, it’s time to call a water treatment specialist. They have tools—like aeration systems or ozone generators—that can handle high levels of hydrogen sulfide. These are the heavy artillery of de-stinking.
They’ll also test your water for things like methane gas (rare, but dangerous) or coliform bacteria. If you get a result that says “toxic,” do not pass Go, do not drink the water. Call a pro.