I don't believe he is jealous of his brother. Megan was also rich before she met Harry and she was very well know from starring in Suits. To be honest, I didn't buy the book but I will read it one day soon. I do think it must be very hard to come out and tell the truth about the Institution not Harry's family as such. He never spoke ill of any of his family. In fact, he wants to be close to them but the Institution won't allow it.