Another damn fantasy novel. Not sure if it contained dragons.

I may be scrambling two books together. In the mid 90s to early 2000's, I read a book that began with a person wrecking their van in a snowstorm. They were then transported to a forest with different pools of water (not a Narnia book). They jumped into the pool and were in a fantasy land (I think they were a female) they had to set off on an adventure and packed cheese and bread, as you do in medieval times. One thing that stands out is there was a wizard who hyperventilated so he could slow his breathing to....escape? Or maybe find a dragon? (Not Eragorn or any of the books by the lady who wrote a million dragon books). Sorry it's vague, I read every book at my local library as a kid so some of it may be jumbled.