X2 on what GraceLikeRain says.
Work and structure, horse needs a routine to realize this place is like last place, he’s still a horse and all will be ok.
Plus being ridden/routine will hopefully get energy (mental and physical) out safely and allow horse to gain confidence by showing what he knows.
If a training barn/program is not an option, then at least get the horse into turnout with friends. And try to establish a daily routine of brush, tack, lunge and (hopefully when you feel safe) get on and at least tack walk. Build from there. Involve a good young horse starter if you can.
You are building the foundation of your relationship - these months are the most critical.
Edited to add: He likely doesn’t know how to be cuddly or that being loved on is a good thing. He was treated as a working horse - in, groom, ride, back out. By putting him into a program, you give him the chance to show you that he knows how to be a good working horse, from which you can then build.
My first ‘import’ came from over 4,000 km away. Got ET kidnapped as I said, landed in a strange new world but still Canada and we still all spoke English and had the same(ish) food. He didn’t know how to eat a treat as he’d never had one, we had to start him on carrots with green tops as he liked to eat the green part and then realized the carrot part is also good. It took him about 6 months to fully come out of his shell and settle in. It is a huge transition when they lose all their people, barn mates and friends.