What Causes Painful Weak And Inflamed Joints With Negative Rheumatoid Factor Test?

Question: I am 24, healthy weight, and my only diagnosed condition is fibromyalgia (diagnosed by a rheumatologist almost 8 years ago). I have treated my fibromyalgia primarily through exercise (yoga, pilates, focusing on strengthening my joints, using regular jogging endorphins to help me cope with the pain, etc.) and occasionally relying on small amounts of cannabis when the pain was particularly severe. I have a mostly healthy diet except that I drink excessive soda (it comprises about half of my daily liquid in take). For a little over a year now I have had painful, weak, inflamed, and occasionally hot joints that I attributed to my fibromyalgia (until recently I did not know fibromyalgia was non-degenerative and should cause only pain, not swelling). 6 months ago a friend bumped into my knee with a book and I felt such sharp pain I almost fainted, completely dizzy and disoriented. I went to the emergency room with a dramatically swollen knee, x-ray was clear, I was given a steroid shot to the knee and I recovered after a few weeks of physical therapy to strengthen the area around the joint. I mention this only because my severe physical reaction to such slight impact may be worth noting. Then a couple months ago, after taking anti-inflammatory OTC medicine to manage my swollen, painful finger joints (an almost constant problem now), the swelling surrounding my metacarpophalangeal joint went down and I discovered a large, bony hard and non-movable protrusion under the skin on the side facing my palm. I saw a Minute Clinic nurse practitioner at my local drug store who stated it was likely a bone spur and that I should see a rheumatologist. I made an appointment but even now I still have another month left of waiting. A couple weeks later I had severe pain in my underarms and hips and hot swelling in my lower back. I went to the emergency room thinking my coccyx was broken because the pain was so intense. The ER doc thought I might have some sort of early onset arthritis, but blood tests showed no indication of an immunological response. That said, she still suspected it to be some sort of arthritis and, again, I was recommended to see a rheumatologist. Just now, a couple weeks later, I found myself having pain and limited mobility with my left elbow. I found that I could not bring my wrist all the way in the direction of my shoulder. When I touched the inside of my elbow, to my revulsion, I felt a hard movable lump, a bit larger than a pea. My touching it shifted it slightly and now I have mobility in my elbow again, but I feel strong, throbbing discomfort. I do not now, nor have I ever had any discoloration or rashes or redness associated with this or any of my inflammation or pain. At this point, I am even more alarmed and confused about my body than ever and the wait until my appointment is even more difficult. Having explained as much relevant information as I could think of, do you have any explanations or recommendations for me to think on as I wait for my doctor's appointment?