Why Have I Had Joint Pain For A Year And A Half, Starting In My Fingers And Spreading To Multiple Joints, With Swelling And Stiffness?

Good evening doctor, Past 1and half years I have been suffering with joint pain which started first in my index finger and it had been inflamed like a sausage.... I even had white patches appearing on my scalp which I thought it s a fungal infection and was applying an antifungal ointment topical application.... then I had visited a doctor when I had swelling on both my feet ankles and he diagnosed me as polyarthralgia and prescribed couple of tests that RA factor , ESR elevated, Crp positive after which he gave a tablet that etos 90mg to take once in a day preferably morning.... for the scalp infection I had visited a dermatologist which she examined and said it s scalp psoriasis and prescribed couple of medicines that s coal tar shampoo, omega tablets etc...... nothing worked infact it became more aggressive and its all over my scalp and now started spreading towards my forehead, ear inner and outer scaling started, flakes which looks like dandruff and is whitish in color..... the bone specially my finger joints, wrist joint, elbow joints, knee joint, ankle joints, my rib the last one, my back bone, the femur joint has been affected, my daily activities has be completely affected due to pain and restricted movements, now my mandible joint too pains when I open my mouth.... I m depressed because I can t be normal again.... I m just 31yrs old post graduate student completed, wanting to join work but due to this condition I can t do anything physically, doctors kindly help and suggest me some ways n means to get my health in proper condition.... my fingers are affected and I can t bend them..... horrible pain and stiffness.... what will be your suggestions and expert guidance towards my conditions doctor????????