Welcome to the forum. Thanks for your question.
There is a lot going on here, and a lot of detail in your question. But one important aspect stands out above all others: your HIV tests. They prove you don't have HIV and that something else (maybe more than one problem) explains all your symptoms.
The HIV blood tests are among the most accurate diagnostic tests ever developed, for any medical condition. Therefore, HIV test results overrule all other considerations: no matter how high the risk of an HIV exposure, and no matter how typical the symptoms, the test result rules, as long as it was done long enough after the last possible exposure. Contrary to your doctor's advice, a negative 4th generation test at 6 weeks is absolutely 100% accurate. The 3 months standard applies when only an standard antibody test is done (and even then, usually 6-8 weeks is sufficient). See this thread, as well as the other link you will find there:
So congratulations -- for sure you don't ahve HIV. (You also describe a relatively low risk exposure, since most sex workers don't have HIV; and your symptoms are not typical for a new HIV infection. The rash of a new HIV infection doesn't behave as yours has. But as already discussed, these things don't matter anyway.)
So my advice is that you continue to work with your doctor about the various symptoms. My impression is that they reflect some combination of a systemic non-HIV viral infection (maybe infectious mononucleosis?), perhaps scarlet fever (strep throat with rash), and perhaps allergy to one or more of the drugs you have taken.
Best wishes-- HHH, MD