I don't know about an overabundance of feelings, but excitement can really flow blood. Plethora has nothing to do with it. I write not theoretically, but from my own experience: I have anemia, and when I am worried, sometimes blood flows and a lot.
Well, here it is more likely not because of feelings but because of excitement. Some people have plethora, that is, an excess of blood in the body. And when the pressure rises, their vessels burst and blood from the nose can go. So I think theoretically, if a person is very worried about feelings, and he has full blood, then yes))