I agree with jonasdouglas1986, Chances are overwhelming that you would get much more complete advice from a doctor who gets a history and examines you, than from random people on a BJ forum. Although IMO JD86's advice is appropriate.
In the US your choice would be between a generalist and a sleep physician (usually listed as "pulmonary and sleep disorders").
In Europe, you may have to see a generalist first, but there are tests that sleep doctors can do that generalists don't do.
Good luck.