I'm being treated for a sinus infection and my muscles feel weak/sore/fatigued all over. is this normal. i'm worried about guillain barre syndrome.

Guillan-Barre : Syndrome is not what you described, it is rather starts as numbness, weakness that spread from below upwards, occurs weeks after having a respiratory or gastrointestinal illness, it is still a rare disease. With sinusitis and upper respiratory infections you can have soreness all over if there is a viral component, the usual rest, fluids and pain killers advice holds true still, wish you wellness