What's wrong with my top teeth? (inward curvature) and what would be my best course of treatment?

Hello and thank you for your great question. I totally understand what you are saying and how you feel.I believe that how your teeth were for years: a lot of crowding due to a very narrow arch.Please consider orthodontics. Braces or Invisalign will help to expand your arch and consequently there will be space to align your teeth properly.Your smile will be improved and you will be happy with it.

You have severely underdeveloped dental arches. This is probably caused by an improper tongue position, as well as other factors (mouth breathing, diet, etc.)To fix it you will need to develop your dental arches and correct your tongue position and any other contributing factor(s). Developing your dental arches is done with removable appliances, followed by orthodontics (braces)Good luck!