>>8969759Ejaculation causes a severe loss of dopamine and oxytocin in the brain, as well as a big surge of prolactin. Dopamine according to wikipedia "confers motivational salience...dopamine signals the perceived motivational prominence (i.e., the desirability or aversiveness) of an outcome, which in turn propels the organism's behavior toward or away from achieving that outcome". In other words it's the neurochemical that makes you want to get shit done, and you lose it when you fap. You also lose a lot of oxytocin which is responsible for sensations of love, well-being and social bonding. All of this great stuff gets replaced by prolactin, which causes a loss of testosterone and is the chemical primarily responsible for helping pregnant women make milk.
http://sites.tufts.edu/emotiononthebrain/2014/11/18/postcoital-neurochemistry-the-blues-and-the-highs/ 