Can I do another FUE [I had 3500 FUE grafts 3 months ago] (photo)?

Your donor supply looks pushed. If you harvest more grafts in this areas where it was harvested before, you may deplete the donor area and become bald there.  There is a limit to how many hairs can be supplied by the donor area. The safe area for harvesting I defined by the lines I drew (the safe area is between the lines) on the photo but as you can see, some of the grafts were taken from the non-permanent zone.  I would not rush to get another hair transplant as the donor area will become more of a problem than the area where you are moving the grafts to fix. You might want to find a doctor who can do a strip surgery for more grafts as the depletion will be less in the areas shown.