I'm sorry you're up in the middle of the night, lack of sleep will not help with the stress of move in day. Today will be the hardest day of all, it is difficult to have to admit you can't cope any longer, and no matter how hard you've tried this move will most likely feel like you have failed him, and you will be looking for reasons not to go through with it. I was the one who had to move my Dad into a care home when my Mum could no longer cope, and after he passed I have had to do the same with my Mum so I have a lot of experience with the second guessing, the guilt and the fear that you are feeling. If you haven't already had the opportunity to set up his room, try to take a few small items from home with you today, a familiar blanket, throw, a small picture or 2 to start with and maybe something bright and Christmasy to warm up the room. Spend some time there with him and make sure you leave for the first time right before a meal if you can so he is actively engaged when you leave. It will be very likely that you will feel a strange combination of grief and sadness but don't feel guilty if you also feel some relief. Take advice from the carers but also do what feels most 'right' to you, if that means going back later or the very next day, just follow your instincts and you won't go far wrong. It may not get easier right away, but once the move is done you will have taken the first step in your new 'normal' and will be able to use your energy to figure out what works best for you and your husband going forward, not just to survive each day. There is no way to predict how long it takes for people to settle as everyone has a different experience so just don't expect too much right away!
Good luck.