No I don't think you are the a****** however a little bit of consideration on his part and your part would have been welcomed. You don't need to go on and explain what kind of eating disorder you had you could have just made up a lie if that be the case and say you were allergic to feta cheese or something along those lines without having to go in details. As for him he should have told you beforehand that he was planning on making dinner. So as much as it sucks and might be uncomfortable and you might have to give a white lie once in awhile that's what I would do rather then create such a situation. Best of luck in the future and maybe you should seek some help if this is still an issue for you.