Then, who designed the designer?

Good question and makes the point that there was no FIRST designer.
Everything comes directly from the previous moment of itself. In
Buddhists terms it's called Mind Stream, or Mental Continuum. It's
pure mind and encompasses everything. WE are the creators of our
world, each of our worlds.

Can you present any evidence that everything comes from the
previous moment of itself?
Can you present any evidence that we are creators of our world(s)?
Aren't you simply saying people imagine everything?