Hi I Have RA, I Have Been Taking Methotrexate For

Hi I have RA, I have been taking methotrexate for 4months and still have bad joint pain. My doctor ants me to try Humira but I am scared because of the side effects . I am a hair stylist and I love my job but its getting harder and harder to do it. I am 44yrs old and I got diagnose in July 2014. What exactly happens to the cells in my body after taking the drug. Plus I already have bad sinus problems which I learn is a problem for some patients. Thanks for the time to express my concerns