Q: Your whole philosophy is based on assumptions about cause and effect. You say that all things have causes, and thus lack inherent existence because all things are dependent on their causes. But how do you know all things must have causes? If you are wrong, then things can exist inherently, and your entire philosophy falls to the ground!
A: "Existence" is a human concept. If you perceive or conceive of a thing, then you cause its existence. Thus there is no way a thing can be without causes. Also, a thing cannot exist without having parts, and these parts constitute causes. In nuclear physics there are some particles which arguably have no parts. However, they do have characteristics, or attributes, and these too constitute causes. Again, things must have causes.
In addition, we live in a world where time is a demonstrable reality. The passage of time necessitates change, and change is made of cause and effect. Thus, where there is time there is causation. When our minds created time, they created causation too. The one cannot exist without the other.
Q: Your argument defeats itself: if nothing truly exists, then cause and effect doesn't truly exist. Yet you use it to support your philosophy! Similarly, why do you think time is real?
A: It is incorrect to say that cause and effect doesn't exist, for while things lack inherent existence, they also lack inherent non-existence. Because cause and effect is a useful concept it is a valid and useful tool. Without tools, we can do no work.
As for time, it is real if we make it real. If we made time not real, through conceiving of it in a different philosophical manner, then, once again it would be impossible for an inherently existing self to exist.
Q: Why?
A: Because a self can only exist in relation to other selves. Relations are causes, which are not possible when there is no time.
Q: Why so?
A: Because relations are human concepts and concepts require time. No time means no concepts which means no relations which in turn means no existence.
Q: Given the existence of time, why does the passage of time necessitate change?
A: Because time is measured by change. If there were no change, there would be no time.
Q: You have given me a circular argument! You say that change is a reality because time exists; and then you say time is measured by change!
A: Yes, the argument is circular, but this does not make it false. You see, we are speaking from the aspect of relative truth. In the end, all dealings in the relative world turn out to be self-referential, and circular. This is because all things exist only in relation to each other.
If you want ultimate truths you will have to look behind and beyond all these words.