Pip's view of Estella does change throughout the novel, although is love for her remains pretty strong. When he first meets her, he is overwhelmed and dazzled by her confidence, beauty and opinions. He wants to change everything about himself in order to fit her view of what it is to be a gentleman. He worships her with a rather unrealistic and naive adoration. As he grows and attains his money, he still loves her, but he realizes that she has faults. Her determination to marry someone she doesn't love, for instance, dismays him. He realizes, through conversations that they have together, that she is a character that has been the victim of Miss Havisham's twisted and broken heart and mind. He understands her flaws, but, he loves her still. The dazzle has faded a bit; he can see her as a creature that has weaknesses and errors in her.
Near the very end of the novel, Pip still loves her, though his love for her is more mature. He has learned to live life without her, and as he confesses to Biddy near the end,
"I have forgotten nothing...but that poor dream, as I used to call it, has all gone by."
He still holds Estella dear in his heart, but has given up ever having her. When he comes across her at the old house again, he is able to tell her that they can be friends, when the last time that he saw her, he had declared that he loved her passionately and with all of his being. He looks upon her probably with more kindness and friendly affection. He went from idolatry of her, to anguish over her, to peaceful acceptance of her fate in conjunction with his. His love was ever there, but the way he thought about her changed throughout the novel. I hope that those thoughts helped; good luck!