Fapping or any other high stimuli addiction will kill your motivation. Anything below the high level of this stimuli will be boring and the brain won't invest any time and effort into it. Video games and porn will kill your social life because connecting becomes boring.
Actually we have a balance scale in our brain which regulates our motivation. If you feel high you have to feel a little low afterwards, that's how the brain stays balanced. An addict doesn't like the low because it's much stronger in comparison to the high he/she feels. So instead of allowing yourself to get into the low, you use again to feel high. And again. Ultimately skewing the scale and messing up your baseline motivation. Allow yourself to feel down and don't judge yourself for it. Just accept it as your brain is recalibrating. You'll notice that once you accept your low state you'll immediately feel a little more motivated to do stuff. Just try to not run from the low.