Well, a lot depends on how precise I want my description to get. The conscious/subconscious distinction is a very high-level approximation; when I get down into the details it's not especially useful. There are a lot of more-or-less independent processes, some of which have self-monitoring functions (and can therefore be considered "part of the self-model") to varying degrees in varying contexts, with varying degrees of cognitive permeability and conscious control.

More generally, I find it often helps to think of my mind as a collection of individual agents with goals that are not quite aligned (and sometimes radically opposed). So, sure, the "self-symbol" "modifies itself" in lots of different ways, just like the U.S.Senate does, but there's nothing mysterious about that... it's what you expect from a system with lots of moving parts that interact with one another.