The phrase "This song reminds me of someone" is perfectly fine and proper to use. It conveys a personal connection or memory without placing blame, making it a sensitive and thoughtful expression.
If you want to rephrase "It's all your fault," you could say something like, "I feel that this situation could have been handled differently," or "I believe there were choices made that contributed to this." This keeps the focus on the situation rather than assigning blame directly, which can help in maintaining a constructive conversation.