Claustrophobic

My 16 year old has developed really bad claustrophobic. We are living in a hotel rn because we were renting a very shitty house that was falling apart. Even our stairs. There was a bad storm which caused a tree to fall on our house. My husband was outside in the storm looking for our dog and the house fell completely collapsed. My son was in the kitchen and had am entire house fall on him. I was driving in it from work. By MIRACLE he didn't die. My husband ran back and dug him out of the fallen house and carried him to the ambulance. He had some broken rips buts was okay none the less. Since he's had severe PTSD and claustrophobic. He remembers being stuck in all that and freaking out. We all share a bed in the hotel room and he can't even go to the bathroom without the door being opened now. The only good thing in all of this is he finally developed a relationship with his step dad, my husband. He actually holds on to him in his sleep. After all my husband was the one who saved him. Going into an elevator he's gripping either me or my husband hand so hard I think he's gonna break it. Anyone who has claustrophobic what do you do that helps.