Ok, first of all you should have consulted your dentist
atleast 5 weeks back, as probably your left lingual nerve
may have gotten injured by the needle used for Local Anesthesia
Now, since you are already using Zevit, Lyrica, & Folvite, for 5 weeks, and still you have no improvement, then the injury may be severe, and it is high time that you cunsulted a neurologist
. Do ask him/her wether adding Neurobion
would help, or would need to see a neurosurgeon. In the meanwhile, ask you Dentist though to fabricate a suitable Oral Screen with an incorporated Tongue Gaurd to protect your tongue for most of the time.