OCD is about fear, which could also be the source of the frustration and rage. It may not be one thing you can pinpoint, but something more general.

Have you tried things like limiting caffeine, if applicable, or doing relaxation techniques? Relaxation techniques help to keep the frustration and anxiety level down, so that when something comes along that is frustrating or anger- or anxiety- provoking, your level is low to start with so the increase is not so drastic and doesn't go so high (compared to if your level is high to start with).

If you can, it helps to slow things down at the time they are happening, so you can see what is happening within you, what are you 'hearing' or saying to yourself, for example. (for me it was that I could do *nothing* right, that everything falls apart, etc.)