In a recent personal study of Atheism, I have examined the Cosmological Argument quite a bit, as one inevitably does when engaging the topic.
The Cosmological Argument is old, and has been defended by countless theologians from multiple faiths over the centuries. It has various formulations, and many brilliant men have brilliantly defended it. However, my experience studying it has been exhausting. The attempts at responses commonly spin an incredible web of frantic theorizing, which is very tiring to wade through.
Ultimately, these discussions leave us with these options:
After awhile, I realized that I simply don't care anymore about anyone's attempts to justify clinging to #2. I don't even care about making a proper philosophical formulation to explain why. I know that matter-energy, and natural laws, are not the source and sustainer of their own existence. I know that intuitively. These things are deaf, and dumb. They are contingent creations of an awesome God, who created them, gave them all their properties, and sustains them. There are no other answers which are even possible, and the proposed alternatives are all fallacious, never answer the question, and are a waste of time.
Why is there something rather than nothing? Because an uncaused God, who is supremely intelligent and powerful, made it. Not a single proton could exist otherwise, and there is no other explanation.
The Cosmological Argument, by itself, is enough. It is a sound argument, and in my opinion, it is best taken simply and intuitively. Let it be enough, and move on to bigger and more interesting questions in life.