My pain shooting down it from my left buttock bone or muscle. it is so horrible. help?

Probably your back: Pain shooting down into your left buttock and/or down your leg is usually do to sciatica or a herniated disk in your back. If the pain is severe you should see an orthopaedic surgeon. At home, i would apply heat and/or ice and see which works best. Try tylenol, (acetaminophen) advil or alleve, which are over-the-counter. Walking may help, and do stretching exercises for your back.