Honeslty - see a doctor.

The advice peole are offering here will either help or do nothing or make your problem worse and if you try all of them - chances are pretty high you’ll stumble across one that will make it worse.

Your pain is a symptom, not a problem. You need to find out what the problem is before you can fix it.

What do you eat for lunch though? For a lot of people where I live, lunch is a quick snack. Breakfast needs to keep you going until about 8pm, with a few light snacks during the day, and the typical work schedule doesn’t really allow anything else.

Clearly I don’t know how nutrition works.

… yeah about that…

Eating the same thing for a week or so is fine, for example when a particular vegetable is in season it’s fine to eat a lot of it, but you really should mix it up more than it sounds like you are.

You can kinda get away with it if you eat commercial breakfast cereals, because they are often “fortified” with a whole bunch of neutrients that aren’t naturally in whatever they’re made of. But they still have too much sugar, so they’re not really a great option. If you’re lazy though - go for that.

What do I eat for breakfast? Normally whatever is left over from dinner, and it’s different every day. If I don’t have any (or enough) then I’ll eat cereal or toast.