hi there,
i may be wrong on this but am drawing on personal experience so here goes .:).
have you been on a diet/loosing weight/anorexic previously for a long period of time?
i know this sounds a little odd but after dropping 3 stone in 2 years through diet(no excercise-really bad) i find i am never hungry anymore and dont feel the need to eat. also i often dont like overeating because of feeling like im "slipping into bad habits".
if it is any of these then i would lean towards a mental issue rather than a physical one. the mind can literally overule the body on this and i did do and still does for me- what i would say is that it has lead to huge health issue for me especially in the liver and stomach so see a doctor or try and force urself to eat.
it could also be to do with anxiety or severe stress or even unhappiness.
the issue with your partner asking you what you have eaten and it creating tension si really normal in this situation. i have had it from everyone- it actually makes it harder to eat sometimes!
maybe try to build up on soups and liquids or when you feel hungry , have something that can be cooked and eaten very quickly so you do not go off the idea. avoid gorging as this will associate negative physical feelings with eating and make things worse. try to eat when happy.
whatever you do i suggest you seek advice frm doctors/councillors which reli helps me.
this is exactly how I feel, at first I was not worried but now I am.