I can imagine. If you suffer from sleep apnea then a Doctor should be your first port of call. If by "Teachers" you mean your Wing Chun teachers then perhaps what they are trying to bring your attention to is something other than the over excited headspace you indulge in. "Forgetting to breathe" in that sense does not mean forgetting to actually breathe but rather forgetting to "Focus" on your breathing. If you want to know "how" to relax, there are two ways. One is to focus your mind on topics which are at least neutral(like breathing) and as such "relieve" your mind and therefore the body from tension. The other is to "Alter" the way you view stressful topics(like work) such that they are no longer regarded as stressful. I would have a think about who might best know how to train the mind and then go and ask them to teach you and pop in to the Doc's on the way if you have to. With Respect, Stealthy.