I Have Neuropathic Pain From Damaged Nerves Around My Mouth

I have neuropathic pain from damaged nerves around my mouth area; result of an osteotomy of my mandible and maxilla back in year 2000. I have read that Potassium is good for quieting nerve function. I have seen Potassium in the form of Potassium Oxide offered by several supplement providers; Nature Made being one. My labs from last June indicate my K level to be 4.1, which appears to be within the normal range... My question is would it be of potential benefit to increase my K levels and if so, is that mineral particularly toxic to the liver ??