What your going through is pretty common man, I can totally relate with all you're saying. The porn sites definitely have a negative effect on your progress wether or not you do MO. It will flood your brain with urges and dopamine that'll keep you craving more. Relax when you can try to walk in the woods and like bigft said use the panic button. In the first sentence you said you remember seeing positive effects from Nofap in the past. Use that memory to push yourself and you can get through the evidence is more like personal experience rather than scientific.