4 months post lower blepharoplasty. Any suggestions?

Generally preserving lower eyelid fat by use of the arcus marginalis release surgery is prefered over fat removal for this reason.  You are now hollow in the lower eyelid area after removal of fat.  The best option for this is under eye filler.  I wonder if under eye filler might have bee a better option for you initially as an alternative to surgery.  I do not advise fat grafting to this area as the scaring created by the grafted fat is also very problematic.

It is common to have some darkness under the eyes after lower blepharoplasty. The brow bone is forward compared to the lower eyelids. This will result in some shadowing whenever there is overhead light, resulting in a dark appearance. If the lower eyelids are very puffy, there will be less darkness as the fat causes the lower eyelids to bulge forward resulting in less shadow. When the shadow collects in the line between lower eyelids and cheeks, it produces a "dark circle" as the darkness is concentrated in this area. Removing the puffiness in the lower eyelids can sometimes increase the darkness.Adding filler to the lower eyelids and cheeks will reduce the dark circle by blending the eyelid-cheek junction and allowing the shadow to diffuse over the entire lower eyelid and cheek, instead of collecting in a circle. You have very thin cheeks, so adding volume into the cheeks will also help bring the tissue forward and reduce the shadowing.