How do I make honesty the core of my work?

You have made integrity the center of what you offer: the true number, given straight, even when no one in the room wants it. That is a rare thing to build a working life on, and it is a solid foundation. It means your value does not rise and fall with the mood of the meeting. Living by that standard is a daily choice, not a settled fact. There will be times when bending just a little would make everything easier, a softer number, a rounded corner. Holding firm in those moments is what keeps your word worth anything. The standard is only real if it holds under pressure. Keep pairing your honesty with usefulness, not just the hard truth, but what to do about it. That is what makes people seek out your number instead of dreading it. You have chosen a good thing to be known for. Guard it, and it will carry your reputation further than any single quarter's story ever could.