John Michael Montgomery has voluntarily checked himself into a rehabilitation treatment center. A statement on the singer's website says Montgomery is seeking help for severe anxiety attacks and a sleep disorder. He has canceled all concerts and appearances for the next 30 days.

"I will be disappearing for a while to try and defeat the demons that have stripped me of my energy of life and good health for so many years now," Montgomery writes in a prepared statement. "I assure you that however long it may take, I'm gonna fight to the end and come out stronger."

Montgomery, known for such hits as 'Sold,' 'The Little Girl' and 'I Love the Way You Love Me,' is scheduled to release an album on his own label in September.