You really shouldn't be taking 60 milligrams of diazepam in one shot. On top of that omeprazole and disulfiram both decrease diazepam clearance significantly.
There's no telling how long the effects will last, as this question is specific to you. If I were to take the same amount with the same inhibitors, I would estimate about 48 hours until beginning to feel sober again.
Don't go out, stay at home, a black out is very possible. Don't take anymore diazepam, any other drugs or alcohol. Get someone to chaperone you as well, to make sure these things are prevented.