I'm writing to you today to tell you that I'm breaking up with you. This is not a decision that I've made lightly, but it's one that I believe is in the best interests of both of us.
I've been thinking about this for a long time, and I've come to the realization that we're just not compatible. We want different things out of life, and we have different values. I'm not saying that you're not a good person, but I don't think we're right for each other.
I know this is going to be hard for you to hear, but I hope you'll understand. I'm not trying to hurt you, I'm just trying to be honest with you.
I wish you all the best in the future.
Sincerely,
[Your name]