Hi Kent ,
I had the same terrible rotten egg smell in my water well.That smell could make you gag ,it was so bad I called the Local county water district and they told me to flush the well with some house hold bleach . I put a quart in at the well head and turned on the water valves in the house for about 10 minutes to make sure anything had the bleach mixture in it . I left it in for about two hours and then flushed the well until the bleach taste was gone . That took about a hour . I did the hot water side at the same time . I turned off the water heater first to conserve electric .
That was 12 years ago and I have not had the rotten egg smell since .
It was cheap and worked for me .
Big Al