A couple of times I've tried WILDing and the ones I consider my best attempts thus far, it suddenly gotquite difficult to breathe. I guess that's the 'Sitting on chest' sensation I've heard about...

It wasn't so much scary as it was very distracting, where I felt like I needed to, at the least, concentrate on breathing to the point it screws up the WILD attempt... I suspect it's all in my head and this is normal but... Insight on the matter or advice on it would be preferable.