1. Take out all your spark plugs
2.clean out with brake cleaner
3.go to a local auto parts store and buy a gsr valve cover gasket kit. $20 max.
4.install it. Clean your spark plugs down with brake cleaner and a clean rag.
5.put your spark plugs back in and vale cover back on....shouldn't leak anymore oil if you performed this correctly.

Now as far as your car running like shit it might have been those spark plugs that were drenched in oil. Check that first and give us an update.

Don't worry about every1 else on here they are just busting ur ass because they have nothing better to do.

If you need further help or want me to fix it then let me know and PM me.