Lost a lot of fat & replaced with muscle, what to do with my face? (Photos)

With weight loss the skin can hang and age the face. Looking at your photos I'd suggest a face lift to reposition the soft tissue

Moderate facial aging treatment in the male patient. You would benefit most with a full deep plane face/neck lift done by a very experienced surgeon. With a proper cheek lift you may not need cheek implants. Also a lower lid blepharoplasty with fat transposition will help along with soft tissue grafts to you naso-labial depressions. An in person examination will give a more detailed plan. The scar for the facelift should be placed inside the ear and NOT in front which leaves a noticeable scar.

Loss of volume over your cheek bones resulted in flat, almost concave cheeks. This is due to a relatively small cheek bones you have.. Augmentation of the cheeks with cheek implants, possibly combined with lower blepharoplasty is a procedure to which I would give priority over mid or full face lift.

Yes you need to both remove excess skin via facelift and replace the volume since you loss them from your weight loss. Nowadays there are fat-like biologics from MTF you can use if you have no fat any where else. Sometime dermal fat augmentation might also helps by removing the excess skin elsewhere in your body to put in your face--this is if you do not have the fat for liposuction. Cheek implants will be more trouble for you long term.