Hey Anton,
I have some lessons that are not shown as bluegrass lessons, but work for bluegrass rhythm. They are basic chord beginner's lessons using the boom chick strum, which is the predominant strum for bluegrass.

I've played bluegrass music since I was 12, and this would probably be a good place for you to start. Just start slow, and as you get used to the strumming the speed will come.

here is the link for the tutorial containing these lessons http://www.guitartricks.com/tutorial.php?input=82

JD

Check out all my lessons
http://www.guitartricks.com/instructor.php?g=all&input=52878