Thanks for sharing the pic! I am sure you are very excited with your first horse.
Your husband did a great job of building you a coral. I do hope that you can get her out of that coral quickly, and with another horse for company.
Horses are very much herd animals, and being in a small coral like that and being alone, he will become very depressed in no time. When they become depressed, they will act out, and become unmanageable.
I don't want this to sound harsh, because that is not the way this is intended, but the sooner you can get him on pasture or at least a good sized paddock, with another horse for company, the happier you and your horse are going to be.