It may be that the pain induced by getting a tatoo is distracting from your other pain, as has been suggested by others who responded. You might be interested in a much better solution, Calmare Scrambler Therapy. It is very effective for enduring relief of neuropathic pain. It uses electrodes to send a "no pain" signal to the brain that overrides the pain signals and, after an average of 10 sessions, shuts it off. See this article for more information: https://www.paintreatmentdirectory.com/posts/calmare-scrambler-therapy-effective-non-invasive-treatment-for-neuropathic-pain