Great advice so far. I'm surrounded by deep, fast water with the Henry's Fork and the South Fork of the Snake River (which, by the way, still intimidates me during the summer months when it's running at 13,000 cfs), Fish what looks comfortable to you. Find wadeable water with a bit of riffle action and work your way up to fishing the deeper stuff. I fish the South Fork (right now at 1,300 cfs) not much differently than I fish the Big Lost River (running now at 86 cfs). I pick the water that my experience tells me holds fish, and it's usually not the faster, deeper stretches. As you visit the water more and get a better working knoewledge of it you will gain more confidence and find more fish.
Best advice given here is DON'T FORGET YOUR WADING STAFF! Critical on whatever water you're fishing.
I forgot my staff while fishing Big Elk Creek last July and severely sprained my ankle while wading - the very ankle I just had surgery on to rebuild and repair it due to that bad sprain. Had I had my wading staff it probably would not have happened.
Good luck, have faith and patience. Trust in your gut and don't go into the water when your gut tells you not to. But return often to that water to build your confidence and knowledge.
Kelly.
Tight Lines,
Kelly.
"There will be days when the fishing is better than one's most optimistic forecast, others when it is far worse. Either is a gain over just staying home."
Roderick Haig-Brown, "Fisherman's Spring"