Please help me understand why my face is so long and masculine? What can I do to feminize it?

Facial feminization for the female. Based on my 46 years of Facial Femininization You only need a Rhinoplasty and an Irregular Trichophytic Forehead Lift with Hairline Lowering. Your jaw is fine! See a very experienced FFS surgeon who can show you dozens of natural results and closeup views of the hairline

I think you have identified the two main features that create a long and more masculine face, the nose and chin/jawline. Your chin is square and the jaw angles are wide. The chin can be reduced in vertical height and made more rounded and the jaw angles can be made less angular and more narrow. I would be careful about vertical jawline reduction because of the real potential for soft tissue sag. Your nose, as you have mentioned, is self-explanatory. Computer imaging is needed to see how you interpret these two facial structural changes.