It always comes back to some kind of yogurt for me. The chobani greek yogurt drinks are my favorite (they have ones with extra protein if you need something even more filling). I also have cycled through chobani flips, the regular fruit flavored greek yogurts with granola on top, peach yoplait, even gogurts at a dire time. I don't love the tartness and texture of greek yogurt but it tends to be much higher in protein than the regular ones. If it's particularly bothering me some morning I'll mix in a spoon of half and half or whatever creamer I have on hand and it really helps with both. But yet another reason why I prefer the drinks.
Warm peanut butter toast is another go to, someone else recced already but I'd like to second.
Or toasted blueberry bagel with cream cheese.
I am now realizing that none of these fit the requirements you've outlined. My apologies.