Thank you very much for the useful information Elizabeth.
The symptoms you have are more likely to be a result of a viral infection (which are know to give generalized body symptoms such as cough, sore throat, joint pains, lymph node enlargement, and fatigue) and its extremely unlikely to be a result of the drug reaction to bactrim (but yes this remains a remote possibility).
There is no test to diagnose this with certainty whether these new symptoms are from the drug; but yes a comprehensive clinical evaluation in terms of a physical examination as well as blood CBC/ESR will help identify the presence of a viral infection.
Usually most of these infections are self limiting requiring no specific treatment; except for symptomatic management in terms of pain/cough control until the body's immune system clears off the infection spontaneously.
Your doctor may also stop bactrim now since 7/8 days have passed and this is usually enough time for an uncomplicated UTI to be treated.
So stopping the bactrim (after a urine test to make sure the infection is eradicated), clinical examination, and blood work should be your next step about which you should discuss with your doctor.
There is no harm in taking Tylenol for fever and pain control.
Claritin or benadryl for cough and throat irritation.
Keep yourself adequately hydrated.
And have rest.
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