Hi. Thanks for your query and an elucidate history. It says you have three different problems. 1. Pain in the low back, reading down both the legs. This indicates a condition called sciatica. And indicates compression on the spinal cord by prolapsed intervertebral discs or lumbar canal stenosis. I would advise you to undergo MRI of the lower spine, Neurosurgeon s opinion and proper treatment which may be physiotherapy, injections or surgery. 2. Your another problem is related to nausea, chest pain and sweating. Cardiac check up is normal hence the worry is reduced. It may be related to GERD or something, needs upper GI endoscopy. 3. Now you have pain in lower abdomen. It depends upon associated symptoms like changed bowel habits, bloating which you have not mentioned. Ultrasonography, clinical evaluation will help for the proper diagnosis and gives plan for further treatment. I hope this answer helps you.