How do I get back to my old look and fix the fat/muscle loss on parts of my face? (Photos)

You would do great with facial fillers, such as juverderm, voluma. That will give you immediate results that last up to a year

Hello and thank you for your question.  The
best advice you can receive is from an in-person consultation.  There are many options to treat volume loss/changes in the face including fillers, fat grafting, and facial implants.   Make sure you specifically look
at before and after pictures of real patients who have had this surgery
performed by your surgeon and evaluate their results.   The most
important aspect is to find a surgeon you are comfortable with. I recommend
that you seek consultation with a qualified board-certified plastic surgeon who
can evaluate you in person.
Best wishes and good luck.
Richard G. Reish, M.D.
Harvard-trained plastic surgeon