Welcome to our little asylum.
Your description sounds a little like the
www.asstr.org selection "Nurse Kathy" about a young man named Danny, but that story doesn't seem to go on nearly as long as you describe. More specific details really help in a search like this -- lots of porn out there, it IS the Internet.
They also feature "Sister Pippa," and Literotica has "The Compassionate Night Nurse," although about an older male.
addendum: the best thing may be to just relax about it right now, especially as it's already been a long time. You never know when one more piece of information may pop back into your head -- the name of the website, the name of the story, the name of the author, even any of the proper names used in the story itself, or specific words or some specific phrase from the story which could be plugged into advanced Google. Sounds pretty hot, I do hope you can track it down.
also: not to push my own product too hard, but if you look out on the master menu page of this Archive you find we have a so-called Addventure. I've written a couple thousand episodes for it, and this reminds me a bit of a thread of mine called DHAMP: The Andromega Strength. The male is a bit older than a "boy," and there's no attempted porn career, but maybe it will tide you over. Also, I've contributed some episodes about a young man named Francis, who gets treated with a drug called Cumalot and finds himself jacked off by nurses.
