I'm a flippin' side sleeper also. One thing that helps me is to place a firm foam pillow between my knees. I find it keeps my lower back/hips in a more natural position, otherwise I end up with some discomfort.

I'm the "guest" who began this thread, now registered on the site. The breath holding thing is difficult to understand. People who have heard me do it tend to describe it as voluntary, not like I'm choking or unable to breath because of an obstruction. It is hard to ignore the possibility of a psych...