I'm the picky partner in my relationship. I don't throw tantrums when my partner eats something I don't like, but I dislike it when he eats meat and won't kiss him afterwards. I do this because I am a vegetarian and dislike the idea of having meat touch my lips, and also because I have carniphobia. However, even if I still feel a little uncomfortable, I will kiss my partner after they wash their mouth and brush their teeth, but I like to wait a while obviously. I think this is a reasonable request, it makes me feel comfortable and it doesn't take away anything from my partner except a few minutes kiss-less. I don't throw a fit, I don't cry and start a tantrum, I just ask that he respects that and we both agree.

That being said your partner is being way too childish and picky. There is nothing more you can do after brushing your teeth, it's really unreasonable of him to complain and act this way after you eat anything he dislikes. And this is coming from someone who is super picky. If he can't deal with you eating something, just leave him alone, picky eaters are hard to change.

At the same time, get him to cook. He knows how he likes things, he can make his own food, and there will be a lot less stress. I know if my partner makes me food I might have a problem with it, so I try to make food as much as possible so that both of us are satisfied. That way I can have my food doubt-free and my partner can have their meal, and no one is upset. Sometimes he might not be comfortable with cooking something (for example I can't cook meat) so maybe compromise and cook things you like for yourself while he cooks everything else, that way things get fixed.

I'm not going to lie, living with a picky eater can be a nightmare. Unless you are willing to both compromise and work for a solution together, you may want to consider moving on, picky habits are hard to change, especially without help from both parties.