What does si seulement tu savais combien je taime si tu savais que tu es mon tout. peutetre alors vous savez exactement combien vous signifie pour moi je taime mean?

Translation: (Note, I made some assumptions about missing punctuation)

If only you knew how how much I love you. If you knew that you are my everything. Maybe, then you would know exactly how much you mean to me. I love you.