Lilian,
according to Edyta (who knows Croatian) there is no "so" in the source-text. Is it possible to say "I love you much" in English? In Swedish there is a slightly difference between "så mycket" and just "mycket".
In English the most usual expressions are:
"I love you so much" and "I love you a lot"
Although it wouldn't be grammatically wrong, we don't usually use "much" alone.