I absolutely get physical symptoms upon the moment of confrontation. Now, I am generally outspoken, and my job has me talking in front of people everyday, no problem. But the anticipation and stress of confronting an alcoholic is a whole other animal. It's stressful because you don't know how the A is going to react, but you can anticipate that it won't be good.
I think part of the reason that As don't get how hard their drinking is on others is that they can't SEE or FEEL the anxiety and stress that we feel. I get short of breath, rapid heartbeat, pit in my stomach and nausea just before and during a "the talk." One reason why I don't nag or complain about AH's drinking very often is that I cannot physically deal with anxiety of the confrontation on a regular basis. I have stated my concerns about and objections to AH's drinking very clearly on more than one occasion. He chooses to disregard my concerns, so there's nothing left to say.
Anyway, I think the physical reaction is very normal--it means you care deeply about your wife and her health and the health of your marriage. The only other situation in which I get those kind of sick nerves is right before I'm about to give a closing argument in a jury trial (I'm a lawyer). I always say that if you stop having trial nerves, you should pick a different profession because you've stopped caring.
I know this is difficult, and I wish you luck and peace as you decide how to approach your wife.