I have neck, shoulder and arm problems and the majority of it is on the right side. I had a very heavy ceiling fan fall and hit me on the head, the blade cut my right eyebrow. It wasn't long after that I started having symtoms. It took a long time and many doctors before we figured out what was wrong. The pain has gotten much better with medication. My doctor has me taking prozac and pamelor. He is telling me that the prozac helps the headaches and the pamelor is for sleep (getting enough and quality sleep eases the pain). I was really resistant to taking medication (especially anti-depressants) at first but now would not be without them. I am so much better. I still have pain everyday, the worst in my neck and shoulder, but It's managable.
I think you need to continue investigating your elbow. The fluid makes me think there is something they can do to relieve some of the pressure or at least give you some flexibility. I know that I will be requesting an MRI on my shoulder when I see my doctor next month. I really think that there is something wrong with it and will feel much better having it scanned.
Welcome and hang in there!