Two totally separate things that have worked well for my bench...
1) High frequency, pavel-style work (I raised my bench back up to my competition best, like +20 lbs, in 3 weeks doing this). In that you seem to have approached things on this end (i.e. the higher frequency stuff), perhaps this is not for you.
2) A combination of one day dedicated to the bench, and another day dedicated to an "overload" movement in the form of a floor/rack press. Volume accumulated on both with triples/5's. I did overhead stuff on the middle day.
Have you ever played with any rack or floor presses? Getting the bar to start right at/below your sticking point seems to do good things.