Hi! I Was Given Amoxicillin For A Sinus Infection-dosage 875

Hi! I was given Amoxicillin for a sinus infection-dosage 875 mg twice per day. I have taken Amoxicillin in the past and done great, but dosing was less ( 500 mg three times daily). I am an adult, but weigh only about 105 lbs. After just two doses, I became rather nauseous this afternoon and just threw up. Do you think this is related to the Amoxicillin and/or the dosage I'm on?