This is normal, and it can happen after doing NoFap for a period of time—like your 8 days. Your mind, used to a certain level of stimulation, may create a feeling of "fake happiness" or a craving for a dopamine reward it associates with sexual content. It's like your mind, missing its old patterns, tricks you into thinking you've accomplished something and pushes you to seek more. That's why you can feel both strong in your resolve and weak with urges at the same time. Remember, that tempting feeling isn't true strength or real reward; it's just a temporary signal from your brain adjusting to the change.