Do I have a weak chin? (photo)

You have a few options to improve the projection and symmetry of your chin and profile. If you’re not sure you’re ready for surgery, but still want to improve and strengthen your chin, I’d suggest augmenting your chin with Sculptra and/or Voluma. If you like your new look, you can make it permanent with a chin implant. I hope that helps.
 

Yes, your chin is small for the profile of your face.  You also have an underdeveloped jawline.  Adding a chin implant first can provide projection of the chin and better balance of the nose, lips, chin complex.  Afterwards, I would consider fillers at the angle of the jaw to better align the posterior jaw.