Swollen painful middle knuckle?

About 2 months ago, I started excavating a 200 year old well which had been filled in with large boulders, among other things. After about 2 days of lifting these rocks from the hole, my middle knuckle on my right hand began to hurt and I lost some range of movement. I went back and did some more excavation last week and the symptoms have now gotten worse. I can't lift a cup of coffee because the lateral pressure on my middle finger is excruciating. If I bump the finger on something it sends pain back through my hand. The knuckle is swollen and without health insurance, I at least need to know what is wrong. I did nothing to cause a break or fracture just heavy lifting. In the morning I run hot water over it and mage it which helps but only for a short while. It seems to subside somewhat throughout the day as I use it. But then in the morning it's back to square one. It even wakes me up if I bump it in my sleep. My profession involves lifting but this is hampering my ability to do that. HELP PLEASE! :(