Hi I Have Sero Negative Arthritis.(missing The Rheumatoid Factor) I

Hi I have sero negative arthritis.(missing the rheumatoid factor) I have been going through a major flare up for about four months.I had bloods taken one week ago and I found out today the crp reading was 16.I was in agony over the weekend so I went to see an out of hours doctor who thought it was a severe flare up and gave me ponstan 500mg tabs 1x3 times daily.after just 3 tablets I had complete relief. Have you any advice for me.I attend an arthritis clinic every 3 months for past 3 years but my health has deteriorated rapidly in this time.I'm exhausted all the time.I'm not sleeping. I can't Remember the last time I was pain free.I have absolutely no quality of life.I recently went to France for two weeks holidays but I gave the majority of the time in bed with pain.