翻訳 - フランス語-英語 - Pour celui que j'aime...

Ce texte est destiné à une personne très importante de ma vie.

note : j'ai corrigé "je te l'ai déjà dis" avec "je te l'ai déjà dit"- voir lien dans le post dans le champ de la discussion - (09/16francky)

Original Translation:
You're the man of my life, you know it, I've already said it.
You mean everything to me.
I would like to stay by your side for the rest of my life.
I swear to always love you, no matter what happens.

Changes:

Punctuation now reflects the original

Je te l'ai déjà dit =>
I have already said it TO YOU =>
I have already told you

You mean everything to me
Okay, but the exact equivalent, "...are..." ,is just as possible (and even preferable, actually) in natural English, so please choose the exact translation if it's viable

I swear to always love you
is grammatically correct, but not usually used in such a romantic case;
I swear I'll always love you
is more natural here