I get easily stressed and it brings serious problems in my coccyx bcos all my low back muscless get stressed. What can I do?

Stretch. First try to reduce the stressors in your life. I know that sounds crazy but we can all shed some of the things dragging us down. Exercise is an incredible help for most back problems and by exercise I suggest walking or swimming or many of my patients enjoy "tai chi" an eastern exercise that is very helpful in low back problems.