Rest your back on a wall or any solid surface and bend forward with your waist gradually. Do it as if you are reaching for your toes, but don't force yourself to stretch too much. Take deep breaths to relax and repeat this for a few more times. More tips are available on wellbeing-support.com/7-exercises-to-get-rid-of-back-pain/.
If you need Immediate relief-put your Bed Against the wall. Lay on the bed with your Legs Raised Up Against that wall.Get your bottom as close to the wall as is Comfortable.The legs must be Running straight-up so that No Pressure is felt in the injured area. This action will sorta put your Body in an "L" shape.You"ll Love it! I sure do.You can also Bend your lower legs Inward a little for Variation.Stay that way for awhile...then Slowly get up,stretch Gently, and go Rub some Ben-Gay on the sore area.WestieJ.
Sleep on a hard surface without any pillow under your head. If it persist for more 3 days see a doctor for specific medical advise. Failure to diagnose properly for back pain in time can seriously harm you.