How To Treat Pinched Nerve At Back Leading To Severe Pain?

Hello, I have what seems to be a compressed or "pinched nerve" in my lower left back and into my buttocks region that came on very abruptly about two or three days ago. It is VERY painful and with sharp pains when putting any weight on it and uncomfortable dull aches while trying to sleep. What do you suggest? I've tried putting some traction on my leg by letting it dangle but it hasn't helped. I would really appreciate some suggestions as I'm losing money by not being able to work. Thank you, Greg