"I really like you" text. Would it be appropriate?

[Mr]

The girl I like I follow on twitter and she said she wants a text on dec 21 that says "If the world ends today I want you to know I like you." And I really like her and its quite clear to me and everyone else that she likes me too, so I was thinking of sending her a text tomorrow, we text everyday almost all day, saying "If the world ends today, I want you to know i really like you!" But I don't know if when I tell her how I feel I want it to be through text message. Would it be better to say the same thing to her tomorrow but in person at school? Thank you in advance for any help.
edit: meant to add: I've always been kinda shy, although that has changed significantly in the last year, having this as an "excuse" might make it easier but I don't know if it would be too cheesy.