Insecure attachment or something else?

I recently went through a very fast but serious relationship. From day 1 he wanted to be my boyfriend, told me I was marriage material, told me I was the most amazing person he had ever met, and constantly told me how special our connection was. We spent 2 weeks straight together, I stayed with his family and he constantly made me feel like I was the most important person in the world. We both had to go our separate ways because we lived in different places and decided we would keep in contact and see each other again soon. He was very genuine the entire time we were together but as soon as we went our separate was he told me he was insanely busy with work and we basically stopped talking. I told him I wanted to come visit and he told me it was "too soon" and he was too busy for that. I went to my psychologist today and she said he has insecure attachment, he rushes into a relationship and puts the girl on a pedestal and then gets distant, she said it was a textbook case. I cannot find any articles online about this type of insecure attachment she says is textbook and was wondering if anyone had any insight on where to read more about this or if there's a different name for what it is he exhibits because I would like to know more about it.

fearful-avoidant, is it? https://en.wikipedia.org/wiki/Attachment_in_adults#Fearful-avoidant

Could also be dismissive-avoidant...