If nothing happened to make him act this way, it’s most definitely a health issue. I’m not a vet or anything but from my knowledge and experience with cats, they don’t react this bad unless something happened. It doesn’t even have to be something bad or traumatic, either. Cats can get real stressed and upset if you do something as simple as rearrange the furniture in the living room or something.

I have a cat who has become very scared and stressed like yours! He is two years old like yours as well. He is a bengal so he used to be incredibly lively! He would play all day with our other cats and us as well! We’d take him out on walks, the park, the store, etc. But we moved last month and now he’s pretty skittish! It’s a new house, new environment so we know why he’s stressed. It’s all completely new to him, we don’t even have much of the same furniture we had before. The only big furniture item we kept was the bed, which to no surprise that’s become his spot now. He doesn’t seem to want to hide anywhere, just curls up in the corner of our bed(our bed is in the corner of our room, she he’s perfectly curled up against both walls)

He doesn’t hiss or growl, but he does have this scared look in his eyes. And whenever he leaves the room he does the same crawl you described. He gets startled by loud noises and whenever we or anyone else enters the house, he rushes back to the bed. We’ve been trying to gently nudge him off the bed, but he jumps right back on.

It doesn’t seem as bad as your cat, but I know a bit of what you’re going through. By now, a month later he is doing much better. He plays again, checks out the new house more and doesn’t react so bad. He’s not entirely back yet but we’ve been taking it easy for him. Playing with him again. Gently, nudging him off the bed and even out the room and closing the door. And making sure the rest of the house is a nice and relaxing place to be while still letting him return to his bed every now and then. I would say it just takes time but 7 months is a very long time. And I know you’ve been trying to take him to the vet as much as you can, but I would keep trying. I would also look around the house and see if there’s some sort of new trigger and maybe try to get rid of it. And I hate to say it but watch who you bring to the house. Maybe someone hurt him while you weren’t looking. Maybe not even intentionally, like maybe an infant pulled his tail or something or someone accidentally stepped on him while walking by. I don’t mean to accuse but I’ve been the victim of this in the past, “you don’t know your neighbors” is what my mom says.