What is Aristotle saying about a Tragic Hero ? Please help ?

I think your essment of what Aristotle said sounds pretty accurate. I don't think, though, that Othello's main problem was his jealousy. I think his main issue was that he could be manipulated in the first place. I don't know what that would be called. Maybe being too trusting, or a bad judge of character? He misjudged his friend and his wife, but he believed the one person who hated him.