Numbing the nerve


i have SPMS and have been experiencing trigeminal neuralgia for a few years, my GP has tried several different medications, but none are stopping the pain completely, although they do control it, so I can eat, talk, brush my teeth etc. The other day, I went to the maxilla facial clinic and had an injection in my mouth to numb the nerve - this anaesthetic lasted a few hours and was to give me an idea of what to expect if I opt for the longer term one, which lasts about 6 months. I do think that a numb face and mouth is the lesser of two evils, but, because I couldn’t feel it, I have damaged my tongue and inner cheek by biting them when eating and now I’m really not sure which path to choose. Has anyone experienced these injections, how did you get on?