This phrase with the word "how" could be written in another way, because is so weird like that.
"I would like to explain you all my love and how intensely it is, but this same love is so precious , so pure, so beautiful, that is impossible for me to stand.
or
"Explain you all my love and how intensely it is, would be my greatest will, but this same love is so precious, so pure, so beautiful, that is impossible for me to stand.