I'm just some person so take this with a grain of salt but here are my thoughts:
the first one is not your struggle it's your brother's. to me I would feel uncomfortable reading about how much you overcame the adversity of somebody else's struggle. There's a way to write this sensitively but I'd be quite cautious.
the second one is your struggle (and I'm truly sorry you had to experience that) but you do not describe your actions but those of a coworker, it would be more persuasive if you talked about what you personally did, especially in question 2a
the third one seems the most on-target but I would still be cautious of the issues that plague the first one (make it about your adversity not what your family members faced)
This is a rlly good set of ideas, I think ur gonna do great!! : )
