If our traits came about through evolution, such as the desire to help, the aversion to stealing and murder, and other moral and good feelings, then there is no good in essence, there is only utilitarian morality, such as I will not steal so that I will not be stolen from, and feelings that came from a random mutation that simply survived. What do you think?

You are confusing the question of how our tendencies were created with the question of whether and why it is right to act in this way. These are two different questions. It is certainly possible that evolution created an altruistic tendency, but that does not mean that altruism is right/appropriate. Our conclusion that it is right, if there is one, is based on various philosophical assumptions and arguments. In other words: that altruism is beneficial for survival is a fact. That it is right to be altruistic is a norm. A norm is not derived from facts (the naturalistic fallacy).
Some argue that since evolution created it, there is a doubt that it is not true but was simply instilled in us. But this would be a skeptical question, and you can raise similar questions about any claim, not necessarily about values. For example, the principle of causality, induction, mathematical theorems, and natural laws are the result of considerations made in reason and observations, and these are two faculties that evolution implanted in us. So why believe them? This question itself is also asked with these tools, of course.