Not really, I believe that some concept have material realities (capitalism for ex is a mode of production), so it seems - after looking at the philosophical concept because I'm not an expert - that I'm not really a "nominalist" but there are some good ideas in it.
Because the only immaterial things in self reflection are "qualia", the "raw feelings" of the process, the "experience" of self reflection.
But self reflection is not just a feeling, it's a material process happening inside the brain, before even the fact of you being aware of it.