plumbers,carpenters, need some help

I hope you did as 68er said and scabbed a piece under the edge where you overshot the joist in the right of the photo. If not it will always be flexing there.

I see you have one of my favorite tools there. A Dewalt 18 volt impact driver.

Jack

Did you mean the left side, or have I missed something in that pic. Looks like enough lumber under there park on.