I think you diagnosed your own problem - Viagra, Cialis & Levitra all work by increasing blood flow to the penis, then you add the Nitric Oxide booster & L-Arginine, which ALSO increase blood flow, and you just overdid it. As they say, honesty's the best policy, just be upfront about it & tell your GF what happened, you're in pain, etc., and just say look, I need to take it easy for a week or 2 & I'm sure she'll understand.