Used too much oregano how do you salvage the spaghetti food?!
Answers: Add one can Muir Glen Organic diced tomatoes (they are very sweet without any added salt or sugar) and cook a bit longer. Taste, adjust seasonings. You may need to up the red pepper flakes to offset.
Add more of the other ingredients and make a larger batch of sauce. You can freeze the extra in individual portions for later meals.
Only thing you can do is take out about a quarter to one third of it and add more tomato sauce until the taste is acceptable. Sorry, that's the only solution I can think of. Save the removed and freeze it to add to the next batch of sauce since it is already seasoned.
Dilute the sauce with more tomato sauce then season to taste.
AmyJ has the only fix answer
If you have already combined all the ingredients over the pasta and don't want to freeze any of it, put your entire batch of spaghetti in a colander and run water through it to get rid of the ruined sauce. Then in a large pot, heat up a jar of store bought spaghetti sauce and add your spaghetti -- the contents in the colander -- and slowly heat, stirring occasionally, until entire batch is hot..
Otherwise, Amy's suggestion.
Add more tomoto sauce. It will automatically dilute the taste of the seasonings.