Is it possible to have a viral illness that lasts 8 weeks or more?

Not likely: If you have been ill for this duration of time you should go see a doctor. Hope this clears up quickly.

Depends ondefinition: Agree that it is not typical for viral symptoms such as fever, muscle aches and pains, sweats, and malaise to last that long. However, post viral syndromes, autoimmune diseases, and chronic bacterial diseases, when left untreated, can last this long, usually with waxing and waning periods. An out-patient infectious diseases specialist can be consulted to help find the cause.