I'm not quite sure how to understand what is being said in bold below. The first part is him thinking that he could forgive her a little since she is more beautiful than the ugly girls that have hated him. He then says however, it might actually be ....
Unfortunately 一段階ショック doesn't seem to be a common phrase when googling it, but the hits suggest that it is to do with the "first step/stage" of something. Most of examples I saw on google were describing the first stage of "pet loss" as shock.
Would anyone be able to help me understand what he means?