"I asked exactly how many onions and how many mushrooms were used in my meal"
And you need to be exact? Can't use an estimate?
Mushrooms are 6 calories/oz, onions are 12. They are low calorie foods, why is an estimate not close enough? Does the thought of being 10-20 calories 'out' cause you a problem? Fussing over low-calorie veg when you're happy to eat 150 calories of chocolate - no, sorry, it's not the ingested calories, it's the level of detail you're determined to oversee here that has caught people's attention.
The reason people are saying your eating is disordered is because of this need to count to the exact calorie. Confirmed by your saying "I have a morbid fear of ever having a weight problem".
I know, I have been there, albeit many years ago now. I counted obsessively because my life had spun out of control and the only thing I felt in charge of was what went in my mouth. Focussing on the food and its calories was a distraction, a coping strategy; if I'm thinking of the food I'm not thinking about what is making me so unhappy.
No, your husband doesn't like cooking for you, and that is not unreasonable of him. You are treating his cooking as 'the enemy', demanding it identify itself. Either cook yourself, or estimate a little. And consider whether you should do anything about your morbid fear, and what's driving it.