Every V is a little different and sounds like you are doing a lot of the right things. V's are very intelligent and they are also need a lot of personal contact, especially when young. That said, a couple of suggestion might be to keep your crate in your room. The sounds and smells of you in the room with him will likely calm him. Also, could it be that you are inadvertently reinforcing a bad behavior by going to check on him or going to quiet him down? If he learns that if he makes a lot of noise, you will eventually come, that might be what is happening. Again, by keeping the crate in your room, you solve that. Our V, did not do well away from us at night, we put his crate in the corner of our bedroom and he sleeps great. I know that may not work for everyone's space but it seemed to work for us.