Oh, she does, don't get me wrong her feelings are just as valid as his. But in this instance it is the loner that was ridiculed in the past together with the ultra Princess that everyone loves and that gives life to this cosplay and everyone at the shoot lusts for.
This is no contest to see who has it worse. Not at all. But her dream had to do with cosplay, he just wanted to make one for her. Now, after realizing the whole world loves her so much, her dream coming true slowly, he might be left in the dust and she might be off to who knows where leaves him even more broken. She was so into this, she had to remember Gojou being there physically. She actually forgot! (chapter 21, clever placement and paneling) She did not have any proper talk with him in a while. She didn't tell him she liked him. She didn't tell him she wants to wear his cosplay forever. She only thought all of that without acting on it once.
The chapter then goes on, skipping over the rest of the meetup and we are inside of a train with them not having talked at all. Personally think Gojou has every right to "misunderstand" and "fuck up" and "be emo" after that.