I think myself that Harry is torn between two ways of seeing the world . He's partly devoted to his grandmother and doing his duty. Something he's mentioned many times. Duty to the country and his grandmother etc.
He also feels conflicted because his situation has caused him to have trouble finding a wife if rumours are to believed. Chelsey turned him down and so did Cressida on the basis that they didn't want the scrutiny and the lifestyle. His career was messed up because of his Royal birth and he lost that. His mother was made utterly miserable by the system, although she learned to use it to her advantage in the end, but it ultimately killed her. Yes, she was stupid to do away with protection and not wear a seatbelt, but she made a lot of poor decisions partly as the result of being cornered and desperate, not having very good judgement because her only adult life experiences were within the RF.
Harry seems to have a naturally rebellious streak which Diana encouraged, always referring to him in terms which emphasised this. So he has internalised that being a rebel is good. He wants to emulate his mother's charitable work and be seen to be in touch with the people and 'just like us'.
All this stuff is mixed up in his head. He then meets a very strong and forceful woman who appears to be offering him a new life. A life where he can have the happy loving family he always craved However in spite of the fact she was well used to being in the public eye, she didn't understand the system or the protocol, and quickly got tired of it. Felt hemmed in, not appreciated. Resented his family, felt her views were not taken seriously or even listened to.
It's had a very unfortunate effect, as he flails around, desperately trying to please her, to keep her on track. He doesn't see his family doing much (in his eyes) to suck up to her enormous ego and keep her happy. He gets resentful, he becomes afraid of losing her. He doesn't want a repeat of his own parents marriage. He tries hard not to be like his father and ignore his wife's obvious distress. He wants desperately to protect his son from the same things he went through.
He becomes angry, alienated, paranoid. Anything his wife asks for, he acquiesces because he is in awe of her and feels quite unworthy really. He really wants her to be happy, to keep the family he wants so much.
He looks at William and kate and feels bitter that it all seems to come so easily to them. He feels his brother doesn't care or support him, doesn't like his wife.
The family become the enemy in his mind, the reason all the Bad Things happen to him. Much better to make off with the wife/Mummy and child to start a new life away from the nasty relatives , a place he can be free to be himself. He doesn't want to be Royal anymore, he wants to be Harry the Normal Guy.
The wife tells him everything is so much brighter and better out the other side, in the Normal World. If we walked away, she says everything Will be Fine. He believes her. He remembers that his mother felt the same way.
It's all lovely too, except they now have to depend on the FIL for finance and they are right down the pecking order in the RF, which actually pisses them right off.