I've got throat cancer, diagnosed after collapsing in July, and am very positive and upbeat as cancer is not the first time I've stared down the barrel of a gun the last 4 years. 3 chemo sessions down, and next step in November. But after the radiotherapy mask fitting last week followed by CT scan and bolted to the table I'm starting to panic. 

Its so close fitting and I know it's for a reason, and I know it's going to be for 3 mins treatment, max 15 mins to get me in place, and they will cut eye holes beforehand as were pressuring my eyeballs  but what can you suggest to get over claustrophobia I didn't know I had?! I tried counting, breathing, and it was over. But I have to do this 5 days a week for 6 weeks without panicking. I need to get my brain in gear to cope with it. Any suggestions please?