There is a chemical released in the brain during sex that is responsible for the glorious high that is experienced during sex.  This chemical is sometimes regarded as proof that sex can be physically addictive, although that is controversial and not accepted by every authority.

What I do know is that I sometimes experience the same let down some hours after a date.  I think that as the drug wears off, there is a bit of let down involved.

Fortunately, chocolate has a way of relieving those symptoms.  Dark chocolate works best, by the way.

In any case the blues will pass after a few hours after your brain chemistry readjusts itself.

(still not a pharmacologist)

I am still pretty new to the hobby, but have some truly exceptional experiences, so of which I have posted on reviews here.  I choose to use an alias for this post, as I am a little embarrassed about it, and don't want it to reflect on my main handle, or the providers I reviewed.

The experience of the sessions have been, for the most part, wonderful. The anxious anticipation leading up to it, meeting a beautiful new woman, the passion of the discovering a new pair of breasts, the different styles of kisses, etc. Etc.  The after-glow, sense of release.  You get my drift.

But I have noticed that a few hours after each session, I get kind of down or blue.  Not sure what it is all about, missing the girl I just saw, anti-climax after all the energy expended...?  I know it's NOT guilt or remorse.  I'm not horny again, but makes me start thinking about the next session again, just to re-capture the "sexual high.".  Is this the "addictive" part of the hobby, or am I just the only one who goes through this?

I'm not a doctor, and I've never played one on TV, but having sex releases chemicals. Chemicals that make you feel really good.

After a period of time, the chemical effect wears off.

That's all you are feeling.

Wanting sex again? Yeah, that's part of nature's way to propogate the species.

...Thus spake the noble Romans about 2,000 years ago.  Translation: All animals are sad after sex.  Personally, I'm not, I'm energized, but I can see how there could be a post-coital drop in pheremones or something.  My advice: don't worry about it unless it becomes such a  burden you need to stop.