Does anyone have an interesting thesis idea along the heroism theme or masculinity theme for The Red Badge of Courage? I really need help with a...

You're going in the right direction, I think. It's been a
very, very long time since I last read that novel, but when I did last read and teach
it, I was struck by how often the novel builds up the idea of patriotism and of male
achievement in war (mostly in the fantasies of the young male protagonist) only to let
all those ideals fail in the moment they’re most needed and to show the young man
(Henry's often not called by name in the novel) again and again failing in his courage
or fortitude or whatever you want to call it.

You may be
interested in exploring how Henry develops a fuller awareness of things once he’s away
from the crowd of men, when he is isolated and exposed to the horror, for example, of
the corpse in the forest. The alchemical transformation in the final lines of the novel,
the change in the imagery from lead (rainclouds) to gold (the sun’s rays), may signal
that some sort of transformation in Henry has indeed taken place and that he has finally
become a man. In the end, then, you may see the novel as in some ways criticizing the
ideals of “manliness” and “patriotism” yet at the same time embracing some notion of
what a “real man” is, someone who alone faces a crisis and
survives.