Right or Wrong

[LTR]

If I just write: "I Love You," can I write it in capital letters like so. Or would that be wrong?

[Casiopea]

Well, it's not the way it's usually written - it looks like a title - but if writing it that way reflects the way you feel, then write it that way. You don't have to be a published author to exercise artistic license.

Please note, know your audience. Your readers or your instructor might not agree with your style.