"I think combined with the fact this job was on a beach in Cornwall, was sunny, quiet, peaceful, it all really helped. I would go to bed with the mental chatter and slept through for seven hours, I thought I was cured or on the way to recovery"
Yep definitely location playing a major role in your symptoms and sleep. Where exactly do you work? What environment? Do you live in an apartment complex? You never know what goodies your old roommate left for you- mercury saturated carpets, black mold spores, arsenic...