Imgur, please help me find the original painting and artist!

I'm nearly finished with my dissertation (18th-century literary representations of pregnancy and childbirth in England) and this picture is part of it. Yes, it's only one little bitty piece out of one chapter, but it's visually impactful and it really emphasizes the argument I'm making in a particular section. Trying to find the original image--the whole painting, with artist name--has been plaguing me for a couple years now. I gotta cite that shit.

I know you've seen this image as a meme. "You cum yet?" or "TFW she says Don't stop, I'm almost there." It's hilarious, sure, but unfortunately its life as a meme has made it almost impossible for me to find the original on the Web. Reverse Image Search is useless.

I've worked with art historians at my university. Nothin'. I've done every thinkable variation of keywords in Google image search. Nada. I've scoured the online archives of museums and databases. Zilch. I think it's late Renaissance or early neoclassical. Without at least the artist's name, it's proving suuuuper difficult to find the whole work of art.

And so I turn to you, people of Imgur. I know some of you are scholars and art geeks. Do you have any suggestions as to how I might find the original painting and artist's name? Any resources you might know of? Are you psychic and can just tell me what the painting is? Are you in fact the original artist who has somehow survived these last four hundred years (and what are your secrets)?

Help me, Imgur. You're my only hope.