You can say you were diplomatic (adj) and acted diplomatically (adv)
- diplomatic - employing tact and conciliation especially in situations of stress. e.g. "a diplomatic way to say no"
Depending on the tone of your voice, empathic may also fit. ( involving, characterized by, or based on empathy)
- empathy - the feeling that you understand and share another person's experiences and emotions : the ability to share someone else's feelings