Need input about lower back pain.?

I have been having some lower back issues. I often have pain in my lower back, but it ordinarily goes away with rest. The other day I was laying on the couch on my side and my hip started to hurt so I moved. That same night the pain in my hip began radiating into my left lower back and then into my left pelvis. The pelvis pain has mostly gone away, but 3 days later my back is still hurting badly. I can't get comfortable, whether it be sitting, standing or lying down. The pain is now radiating into my spine and my tailbone hurts (maybe from adjusting my posture). I work in a physically demanding environment (lifting up to 50 lbs.) and I am a small person. However, I don't remember injuring myself at work. I have a doctors appointment for Friday, but in the meanwhile I am wondering if anyone has any ideas about pain relief or if anyone knows what may be going on with my back? I am very nervous about the possibilities and I am just trying to rest my mind a little. Thanks in advance.