When we determine in our hearts to share with a tone of kindness and generosity, we have power and strength that is not possible when we are sharp and mean.
Learning to face great difficulty and fear with fearless generosity is not easy, but it is fun. Just like anything else, it is a skill and a muscle that we can all get better at.
Find the person in your life that you have a hard time speaking kindly to (maybe it's yourself) and start now. Call them, write a note, or just take time to appreciate them. Notice how they did it right. Notice what you love about them and tell them. You will never regret doing so.
Oh and one more thing. You can't expect anything in return. You have to do it for the joy of doing it and no more, there is a secret reward hidden in that kind of generosity.