What Causes Shoulder Stiffness With Pain?

I was splitting wood christmas eve and christmas day (I have not done this for a while) and on the 26th I noticed my right shoulder (I am right handed) was a bit stiff. Did not think too much about it. But over last couple of days it has kept me awake at night and been so stiff that it has made getting dressed, etc. difficult. I have almost full range of motion but with pain. The pain is located in teh front of the shoulder where my peck and shoulder connect. Pushing on things - like doors and putting the gas nozzel in the care are very painfull. Occainssionally it hurts bad enough that it feels like my fingers on my right hand go slightly numb. I am 41, 6'4" and 260 and pretty active. Could I have dislocated my shoulder? Thinking I should go see a doctor as it does not seem to be getting better.