Distinguished kindness from always having to do things for people, trying to make everyone happy won’t get you very far. Being a pushover is highly undesirable. If your goal is to be respected, being too nice to everyone all the time isn’t a durable path. Some people might even think you’re not genuine. If you don’t want to do something, say so. If you’ve got a dissenting opinion and knowing your heart that you’re right, say so. Being assertive in a polite courteous and respectful way will earn respect from others even when you disagree with them. Speak up when mistreated. Don’t just take it when someone is mistreating or taking advantage of you. Be professional and diplomatic, but don’t be silent speaking up for yourself. Not always easy to do, but a start is not a bad idea at any point of life.
Stop being too nice & speak what you feel.