Hey Avermont, You are doing great! No, I wouldn't confront the couple who sponsored the A directly. They know. Or, they should, and if they don't it is not worth your time. A polite decline of the invitation is the way you can maintain your integrity and handle things with dignity and class. You are above all of that.
About the anxiety... boy, do I know about that! Still struggle with it, even now in the "piecing" stage. But, breathing is so essential. Also.... "grounding" helps. Anchor your five senses to something... like a cup of tea you can smell, feel the warm cup, taste, feel the steam on your face etc. Drink it intentionally engaging your senses and let your brain just "rest" there for a few minutes. Amazing what that does to calm you for a bit. I also do that with gum or mints when I am out and about.
BTW... look FABULOUS, but not overdone when you meet for finances. Get it done and over with and act like you've got somewhere really important to go.... it will get his attention!