Right first of all, you wanna check for any lumps in the tummy. Just gentle rub your fore finger down his stomach to the vent. If you feel lumps, it could be impaction, I wouldn't suggest feeding in this case, just a vet.
If not however, force feeding could be an option if he won't eat by himself. I would say that they can last a while without eating, especially if you only got him a week ago, they can take a while to adjust.
To get some nutrients in him however, I would suggest getting so Hills A/D dog food (from any vets) watering it down a little with some water and critical care (one tablespoon of Critical Care Formula to about 6 tablespoons of water). I also put in a pinch of calcium for good measures. When it is nice and runny, no lumps, I get an ice cube tray, rub the sides with a little vegetable oil, and put the slurry in the tray, with broken up lolly pop sticks in for easy removal.
I thaw one out, and .5ml of it is enough for one sitting a day I would say. It contains a lot of fat and proteins. I use a thin syringe, and hold the gecko in my non writing hand. With my good hand I gently rub the mouth, from the corners to the nose, back wards and forwards, the gecko should then open his mouth wide, then's your chance. It's trial and error really. Sometimes when they are first fed like this it goes everywhere, they shake their heads and it flings about, getting everything covered in dog food. Just make sure none of it goes up his nose, that won't be nice for him

If anyone else has any better suggestions totally think about their advice too.
I would wait it out a little while longer, to see if he needs to settle more. I notice mine will hunt with the lights to the tanks off, so I feed them their bulk food at night, but they have a supply of meal worms in a dish all day.
Maybe handling him a bit less, and just leaving him in his tank with a hide and some mealworms in a dish might help. You could try varying his diet from crickets and mealworms and moths. Mine absolutely love to chase moths around, something I would never had expected from my boring male. Could you get a picture of his underside, and a shot of his tail?
Hope everything goes ok
