Pain in left side of lower back, stomach

I am having pain in my left side of stomach and left side of back just near to ribs from bottom. I am also feeling dizziness and heavy eyes. It's a very old problem but Dr unable to make a diagnose. Had many times ultrasound and it's clean. I also feel tightness in my left leg and left arm but occasionally not regularly. The major problem is that it's a consistent pain. I also feel discomfort and feels like it's in the food pipe because whenever I eat something or drink it's felt in food pipe in an abnormal way. With these symptoms I also have constipation these days. I feel like I am not able to empty my stomach properly. The major problem I am having is this constant pain. Once a Dr told me it might be due to some nerve blockage so consult a Neurologist for this. I did not consulted a neurologist yet. Please help what could be the possible reason for this as it's a very Very old problem like 7-8 months old. Whenever I had medicine fro. Dr it reduces but not cured 100%.