how did you fill the area? I've used a custom paint match from a reputable body shop that mixes their own paint, applied with a plastic toothpick dipped about 1/3 of the way in to the paint. The paint on the toothpick will sort of "wick" into the void. once it's nearly filled, I apply (same method) some clear coat. I wait for at least a few days between applications. Just the filling process takes about 3 weeks. Then you want to give it another week to harden enough to wetsand. If you are afraid of sanding to big of an area, you can use a 1 hole punch on masking tape, and just leave the exposed "blob" of paint and very little surounding area.
Next step is to wetsand. leave your sandpaper in a water bucket over night before starting. Be sure to use plenty of water,and check your progress after each pass. I only sand one direction (so 1 pass would be, for example, 1 move from right to left). And I also switch directions when moving to a finer grit. I start at 1000 grit and move up to 2500-3000 grit. Then you can remove the tape, and polish the cloudy spot. should return to damn near new.