Undiagnosed joint pain/inflammation

I just turned 40 and have been having problems with my fingers on my right hand and my right elbow primarily, with minor pain in my left hand. This started last summer during a home remodeling project that was very mentally and physically stressful. I began having stiffness and pain in the joints of my right hand, worse in the morning as far as the stiffness goes. It's progressed into very painful joints with redness and swelling in my right hand and spread to the lateral epicondyle (the outer boney part of the elbow). I've been to my family doctor who referred me to a rheumatologist who ran all the standard test. Only thing that showed was a slightly elevated CRP level. Tried steroids which provide temporary relief and NSAIDs. Would really like to find out what's causing this and how to effectively treat it. Thanks.