I just found something that supports something I mentioned above. Rather than post a new topic, I thought I'd put it here.
I noticed that shortly after I quit trumpet playing, I seemed to go downhill. And now I'm really struggling with the problem. I think it's apnea, beyond all reasonable doubt.
So after doing a bit of reasearch, I came up with this-
http://news.ninemsn.com.au/article.aspx?id=78765
Playing the didgeridoo requires a controlled breathing pattern, and researchers believe it helps to train the upper airways to combat the symptoms of obstructive sleep apnoea.