Dear WastingAsparagus,
Work anxiety can be really brutal.
I read a book awhile back that really helped me with it. I loaned it to someone so I don't remember the title. I think it was called "The Worry Cure" or the "The Worry Remedy" or something. I think the name of the psychologist who wrote it is Leahy or Leay. Sorry my memory is not so good. The book was so helpful to me. I hope the person who I loaned it to will return it to me because it had chapters on health worries which is something I am going through now.
Don't know if this book would be helpful to you. Perhaps there are other and better books. I don't know.
Hopefully many people will see your post and respond to it with really helpful ideas. I wish you the very best in your new job and with your thesis. Writing a thesis is no walk in the park. I had a devil of time writing mine.
Sincerely yours, Yao Wen