What Causes Severe Headache,dizziness And Nausea?

Ok I m not crazy....my boss and I are the only ones in the building getting sick but mine is getting worse .....massive headache , dizzy , nausea , confused thinking .....very tired.....some tests have come back negative like mold but now they are testing for CO2 and CO.....this is the 4th week and it s getting so much worse....I almost feel high or drunk....can a blood test be done?