Can monistat 7 burn you so bad inside it can permanently damage your vagina ? almost 3 weeks & i still have a cooling burning sensation in my vagina

No: This medication can't permanently damage your vagina. Having said that, it sounds like the treatment isn't working. It could be that you have a resistant yeast infection, or that you have a bacterial infection which isn't being treated by the Monistat. I would recommend seeing a doctor to get an accurate diagnosis and likely changing your treatment regimen. But don't worry, no long term damage.