Figurative speech in Taylor Swifts "Back to December"

In this song there are several lines of figurative speech that stick out to me. First, "the last time you saw me is still burned in the back of your mind" sticks out. Obviously she is not talking about something actually being burned in to the back of someone's brain, she is referring to a mark that she left on him, a metaphorical mark. She left him with a scar by the way that she treated him and that feeling that he had will never leave him, as if it were a scar from a burn that never goes away. Then there is a line, "you gave me roses and I left them there to die" that may or not be true that he did actually give her roses, but I don't think the meaning is literal. I think that she is referring to the way that he loved her, he was sweet and nice and did things that anyone would hope for like giving roses, and she left them there to die. She left his feelings and the way he treated her and she turned her back and let them die. Then tying in to the title of the song the chorus is "I go back to December all the time". Again, she is obviously not literally going back to December because we cannot time travel. She is saying that she thinks of that time which was in December when she decided to leave him. Following that she sings, "then the cold came, the dark days when fear crept into my mind". Fear did not actually creep into her mind, she means that the feeling of fear came over her, and that they were dark days because of that fear. Lastly there is a line in the song where Taylor sings "So if the chain is on your door, I understand". There is not actually a chain on any door that Taylor is trying to get in to. She is saying that if it is absolutely impossible for him to forgive her and come back and give her a second chance, she doesn't blame him, she would understand. She knows how much she hurt him, but she feels very sorry and hopes that he hasn't locked her out of his life forever.