orgasm is a sudden release of intracellular reserve of neurotransmitters (dopamine and acetylcholine) into inter-cellular space, but those neurotransmitters are also needed for thinking and motor function (what you call "motivation", "energy", "concentration"), they are brain's fuel to function, after orgasm you lose a big part of your ability to think and move until the dope gets back into the neurons (which takes hours and uses energy, that's also why we feel hungry after cooming, for brain it feels the same as a workout session or thinking too much), the solution is to coom less