I told my crush like him by text and he doesn't know it's me who likes him because he doesn't have my number. He wants to know who it is but I don't know if I should tell him. Should I tell him it's me?

Big mistake as what if he doesn't feel the same way about you?  Then you've just made the biggest fool of yourself you could and your school will soon know it too .  The worst thing anyone can do is tell another person they like them in hopes of starting a relationship and often ends with disasterous consequences, so maybe its best he doesn't find out who sent this.  Guys hate being put on the spot like this and another mistake is having friends ask someone if they like someone.