The compression of the sciatic nerve should be around the right side that's the reason you have pain in the left side. That's the reason you cannot sit or stand and it is exactly around the L5 vertebrae where the sciatic nerve passes by. It can also be due to the strain on the left leg, try wearing MCR chappals which would help you to get relieved from pai
If you have low back pain
you can undergo intermittent pelvic traction
where in your half of your body weight will be added in the electronic traction so that that would help you to reduce the pain
, along with Interferential therapy
stimulations which would help you to get relieved from the radiating pain. Apply ice for the pain to get subsided immediately.
You shoulder will become stiff and the movements would be diminished. For the right hand pain
it might be due to carpal tunnel syndrome
, where the pain will be felt in the wrist. You can do hot water
fermentation/ wax therapy for shoulder and for the wrist pain (hand pain) you can do ice therapy which will reduce the pain.