Im going through a similar situation. Had a protected encounter and shortly afterwards had flu like symptoms that lasted 3 days, was diagnosed with ulcerative colitis, muscle and joint pain, hives, brain fog, weight loss. Doctors have run all kinds of tests and all is normal. Everything from my GP to my Rheumatologist. Ive even gone out and have run series of STD tests and all is negative. Only thing that helps me is Gabapentin for the pain. Keep in touch.
On the std forum you say this happened in 2011, and you were tested negative for std. No one can diagnose these diverse symptom claims from here, but some of them could be in your imagination since you said there that drinking sugary drinks makes them worse - Coke can't make these things happen. Perhaps a second opinion from a different doc will determine which of the symptoms are real and a go forward plan to deal with them.