Here is the well-known story of the prostitute from the Children of Israel. She found a dog who was trying to drink from a well. She felt sorry for the dog, so took off her shoe, climbed into the well, gave the dog some water. Because she had so much mercy for the dog, she was forgiven by Allah (SWT) for her sins. The point of this hadith is that she had a deep connection with her good deed and Allah. She is in more need for the reward of that one good deed than the dog needed water. Do not trivialize any good that you are doing.