While I can understand why some might have been appalled by the question as I myself found it off base for such a forum , I truly think the poster was sincere and not trying to be vulgar in anyway. I think he was truly nervous that he might have caught something terrible and wanted reassurance. Dr.MJM handled the question as usual very professional and with class. I would just leave at that, maybe it taught the young man a lesson not to look for kicks in the wrong places and with the wrong persons.
I'm only 36 and I consider it xrated.
I was also uncomfortable with the post but realized that patients do discuss these things with their doctors. But I didn't expect to see an "R" rated message on a public forum. Then again, maybe I'm just an old fogie that has old-fashioned values. Most folks probably wouldn't even consider this "R" rated.
I sincerely doubt you have a virus affecting your heart and lungs from this episode. If the arm pit lymph node persists, you should talk to your doctor about that, but my guess is it will subside. I think you are right that hard beats from adrenaline. You are probably nervous about what you did and the lymph node, this will generate anxiety and anxiety increases adrenaline.
Anxiety can cause a lot of symptoms and they often sound just like you are describing.
I hope this answers your questions. Thanks for posting.