Yes a water flush is you best bet…Plug the hole in the oil pan with a peice of small metal and jb weld. Then fill the motor up with water (the same way you would oil) start it up and run it for a few minutes. This will insure that all your bearings are spun…After you are done with this. Fine a rope, a tree, and a chair…
If you are still around after that. I really dont know how else to help you.
I had a friend with an old Subaru Loyale beater. He ran it completely out of oil, which he didn’t know until he investigated why his car was extremely loud. That thing ran for years after that, and it may even still be around if it hasn’t rusted out. If it’s an old-ass Civic, just fix it and dump some oil in and hope for the best. (but for the love of god park the thing until you fix the oil pan)