I also have rheumatoid arthritis and am on methotrexate. It has made an enormous difference to me, both in the amount of pain I suffer and in the amount of damage the disease does. Yes, the possible side effects are worrying, but lots of people, including me, do not experience them. Yes, it does result in immunosuppression, but that is manageable with care. Regular blood tests mean that your GP can watch out for any damaging effects.
I used sometimes to wonder whether it was working but after a spell of 7 weeks about 10 years ago when I had to come off it because of a dodgy blood test, I know that it does. The deterioration in my condition during that time was crippling - literally! I had to use a wheelchair and could not even dress myself because of the damage it did and the pain was something else! I eventually recovered most of the function I had lost, but not all.
I am grateful that that since then I have not had to come off it again for more than a week or so (when having joint replacement surgery) and most of the damage the RA could do to my joints has been held at bay.
As Marydoll says, the medication is MUCH the lesser of two evils, and one comes to terms with it!
I wish you well!