Thank you for your question. This pain in left leg and hip you are having can occur due to impingement, irritation or compression of nerve of thigh or in back. Most frequently involved nerve is lateral cutaneous nerve of thigh (which is branch of femoral nerve). This condition is called meralgia paraesthetica which manifests itself as pain, tingling or burning sensation of outer thigh. It may occur due to injury to nerve either due to spinal deformity or along its path to thigh by any ligament or tendon stretch, excessive tight clothing (therefore it is also called "jeans disease"), diabetic neuropathy or damage to nerve after any surgery etc. Please consult your doctor to get all these possibilities evaluation in your case for further assessment. Hope this helps.
Go to your regular doc, or if you don't have a regular one, go to the county health department as a walk-in and ask the physician you see there to order a scan of your hip joint. There are many reasons why it might be coming out of its joint that have nothing to do with any recent trauma or strain, which the scan would show this. Then the docs can go from there. In the meantime, when you sleep, try to stay on one side and put that hip's knee under a pillow, to keep it elevated, so it won't hurt as much.