Maybe you’re spending money you shouldn’t. Also, maybe youre spending your heart when you shouldn’t.
My first thought is that there’s something about those first couple of bites that triggers the anxiety. Could be subconscious (well, it is subconscious currently if you’re unaware of a cause).
Are there any particular thoughts that occur when the meal arrives? Even thoughts that occur only briefly to be replaced by others?
This was my first thought. Being pretty poor most of my life, I've had that "oh-shit" gut-punch when going out to eat a lot of times. Money problems suck.
Did you sign up for any life insurance policies with her recently? Add her to your will? Is she currently borrowing something and has mentioned "jokingly" about how she'd really like to keep it?
Not a high probability, mind you, but since the subject was raised...