Post chronic lithium toxicity and withdrawal left me with terrible crawling sensations all over my body. Is it temporary and is there a treatment?

Unfortunately. I can't be terribly encouraging about this. Typically with chronic lithium poisoning there is a large body burden of lithium that is difficult to treat. Often this discovered with time or a new medication that alters kidney function or causes dehydration, causing the lithium level to rise. The symptoms you describe are not unusual. Treatment is symptomatic as for other peripheral neuropathies.