Self comes from a thought. A thought that is believed. Identification with self is strengthened through repeated investment in "I" thoughts.You don't seem to have any more doubts about seeing this, and that's really great.
A good way to have this really deepen, and sink in, is to look at this quite closely for just a few minutes and really examine it thoroughly. Then you can really be certain there is no more doubt. There's an old saying, "know thine enemy". Self isn't really the enemy, but you get the gist.
So if you can give me one last long rant, that would be really great, the hard work can be over. Just focus solely on looking at and talking about the nature of self. Let's go back to those questions:
Where did self come from to start with?
What is it's purpose, it's function?
Do you exist in any way, shape, or form?
The purpose of self is to perpetuate the illusion of separation. "I" believes it's an island looking out at others and the world. "I" is the illusion of ownership of reality through the constant thought stream of commentary on what is. The self's function is to be absorbed in its own dreamscape.
I do not exist as a separate "I". There is existence of this body, thoughts appear, doing is done in daily life, and there are sense perceptions. However, there is no "I" that owns these things. There is no controller; there is no author. To believe there is a controller is to suffer.
All is well!