Ouch

Friday night I started having a slight ache in my right arm. It wasn't bad, just a twinge when I'd reach behind me. It was still around on Saturday, but it still was just an occasional twinge of pain. But it's been steadily growing. I now have a pretty constant ache from my elbow almost up to my shoulder with some pretty painful shoots going through it when I try to do simple things like brush my hair or get dressed or even little things like opening my refrigerator or trying to lift something. I don't even have to do anything to feel it, I just have to move my arm around. I couldn't sleep much last night because there wasn't a position I could lay in that didn't cause my arm to ache. I hate my doctor and am trying to avoid going in to see her, but I feel like I'm slowly losing the use of my arm. Any thoughts? What could be causing it and what can I do about it?

UPDATE:
The pain got to the point of being debilitating, so I sucked it up and went to my doctor. When I can't even wash my hair or put on deodorant without crying out in pain, it's time to do something. I can do a lot left handed, but I can't do everything and my right arm was almost useless. Fortunately for me MY doctor wasn't available for 2 weeks, so I saw someone else. She was fantastic. After a very thorough exam, she determined I have multiple micro tears all along my tricep muscle. It makes using it at all very painful. You have to use your tricep in almost everything you do with your arm, but using it causes more tears and prevents the old ones from healing. So I'll have my arm in a sling off and on for the next week and I got some pretty nice pain medication to get me through until it heals. It's a relief to know it's something so simple, and as soon as my ibuprofen kicks in, I'm sure I'll be much happier. And I have Vicodin for night time so I may actually get to sleep tonight!