Please help me find the name of a film

It's a British pyschological horror film, probably made after 2000. It is set in England. A young man is tricked into creating a loop in time in his mind, by an older man whose wife is terminally ill. The older man, who is a pychiatrist, is using a black magic device to create this loop in time in the young man's mind, in the belief that this time loop means he and his wife will never die, as they will perpetually exist in the time loop. There are no famous actors in the film, and I've been trying for weeks to find the name of it. I watched it this year on TV and it struck a chord with me. Any help would be appreciated. Thanks. Michael.