Andrey Iskanov's Ingression (2010)

After his wife Lucy walks out on him, Alexander tries to seek solace in alcohol and drugs, but the pain just won't go away. He is given the address of a mysterious man who claims to have the answer; a strange, powerful narcotic that will take away his anguish. Alexander can't take any more so he visits the dealer and is given the drug. For a while he feels fine, life is good again, until he realizes that shadowy figures are pursuing him. He tries to escape but there is no hiding from the Ingression.