The risks of HIV in this situation depend of course on your partner's risks--but if he is honest in saying he is HIV negative, clearly you have no worries. Every symptom caused by HIV is also caused by many other viral infections and other conditions, almost all of which are more common than HIV infection. Therefore, symptoms are never a valid indicator of a new infection, no matter how 'classic' they appear to be.
You should ask your doctor about infectious mononucleosis. Many of your symptoms are typical of mono (which usually is sexually transmitted).
Your doc is wrong about having to wait 3 months for HIV testing. Modern HIV tests almost always are positive within 6 weeks. You can get tested now with reliable results.
For more information, search the forum for 'ARS symptoms' and 'seroconversion window' and 'time to positive HIV test'.
Bottom line: Relax. Whatever is causing your symptoms isn't HIV. You can count on a negative test result.
Good luck-- HHH, MD