So sorry to hear he has gone a bit bonkers. Is his cage easy to escape from? Depending on what cage he's got, he might need a bigger cage. I've found once you get up to a 100cm cage our Syrians haven't even been bothered about coming out, never mind trying to escape. Although there are some who need even more space than that!
Have a look at the Barney cage on Zooplus - it's a good price, an excellent size for almost any Syrian hamster, and comes with a good sized house for a Syrian hamster - they need something big enough to build a large nest inside, that is open underneath so they can have normal behaviours like bury hoards under their nest. Also a house that is dark inside so they feel secure and have somewhere to retreat.
It may be that getting his cage just right will mean he will settle and enjoy his environment. To have normal behaviours they need enough depth of substrate (no less than 4 to 6" deep). A house big enough and dark inside. Open underneath. Ideally a shelf or platform they can sit on or sit under, that is easily accessible. Some kind of overhead cover so they don't feel exposed in the cage (eg the shelf and floor tunnels/toys) plenty of floor toys such as tubes, tunnels and hidey places so they have variety and places to go and things to do.
Scatter feeding can also help them enjoy their foraging instinct. I do both - put some food in the bowl and scatter some.
You might need to put cushions on the floor round his cage in case he falls from that height again and secure any doors well (peg or bulldog clip?).
Is his wheel big enough? They need a lot of exercise at night and if the wheel is too small he may avoid using it. They need a wheel of about 11" diameter. 8" absolute minimum and that may not be big enough for him.
This is the Barney cage - read the reviews
https://www.zooplus.co.uk/shop/small...r_cages/189303