It simply means "I miss you". It's derived from the lyrics of Taylor Swift's Enchanted:
This is me praying that
This was the very first page
Not where the story line ends
My thoughts will echo your name, until I see you again
These are the words I held back, as I was leaving too soon.
This is me praying that
This was the very first page
Not where the story line ends
My thoughts will echo your name, until I see you again
These are the words I held back, as I was leaving too soon.
by All_too_bad(Taylor's Version) March 30, 2023

It is an acronym of the lyrics of Taylor Swift's song Enchanted. It's commonly used as a substitute of the phrase "I miss you". The full lyrics are:
This is me praying that
This was the very first page
Not where the story line ends
My thoughts will echo your name, until I see you again
These are the words I held back, as I was leaving too soon.
This is me praying that
This was the very first page
Not where the story line ends
My thoughts will echo your name, until I see you again
These are the words I held back, as I was leaving too soon.
by All_too_bad(Taylor's Version) March 30, 2023
