Since he hasn't improved today and isn't able to move his front legs, he should be taken to a vet to be assessed. He also may have eaten something that is causing havoc with his insides and the concern of the colder temps he was in for so long are even more concerning.
I know exactly how you feel, I had a beardie pass the end of February after 2 days of showing anything was wrong. He was going to the vet the morning he passed. At least you found your beardie and he died in his home rather than out in the cold. If you hadn't found him, you would have always wondered what happened to him. I know that may not help you much right now, but at least he was in his home.
i am sorry for your loss.....a lot of times it is difficult with reptiles because instinctly, they do not show signs of anything wrong until it is too late or they are very sick. In the wild this is a helpful tactic, unfortunately for us, it creates a lot of problems...sorry again
Oh geez, I am SO sorry for your loss, that is so sad. I know that you must be very devastated to have lost him after this terrible ordeal. At least he was with you at home when he passed.