weinzwei, one thing you might try is the nodding drill that Coach Terry talks about in the Easy-Freestyle DVD. Start from a head down position then when you rotate turn your head with the rotation; first 45 degrees, then 50 degrees and then try 90 degrees, at that point your left or right side should be out far enough so you can catch a quick bite of air (IMPORTANT NOTE! Inhale through your mouth and not your nose!)
I only say all this because I've been where you are and to be honest with you it has only been recently that I have been able to breathe and not interrupt my rhythm. I hope that helps.