The speaker is nursing a broken heart and trying to cover it with anger. Every line starts with "I hate," but look at what is being hated: blue eyes, brown hair, a beautiful smile. Nobody really hates those things. The list keeps slipping from complaints into confessions, and the opening line gives the game away: "I hate that I still love you."
Other lines hint at what hurt. The two used to talk non-stop, then the other person began ignoring them, and now they're with someone else. The detail about blocking the person who hasn't even noticed is quietly sad. It suggests the speaker is trying to move on, but nobody is watching.
The final line breaks the pattern. It runs on, without pauses, as if the feelings are spilling out. The speaker admits they can't hate this person, and the "hate" turns inward: "I hate myself." The mood is raw, bitter, and tired, the sound of someone who wants to stop caring and can't.