What exactly is happening with my teeth and will whitening it it make the yellow squares fade away? (Photo)

So I used to brush very hard and used an electric toothbrush aggressively for 2 years so my enamel is likely eroded a bit. I have no sensitivity but I can see my dentin through my enamel, like a full square. Is this normal? Will whitening help blend it in or do I need veneers? The picture don’t show it well but it’s more noticeable up close. I don’t mind the clear edges just that the squares go away or fade.