please help, English to Latin

i want to send my friend a valentine in latin because she's a wiz in Latin so can anyone help me translate this?

Whose gift this is you cannot know.
My heart is in your keeping though.
You will not mind my writing here
To tell you that I love you so.
I know that you must think it queer
For me to love and not come near
My love for you is dark and deep,
But it's a promise I will keep
As from afar I watch and weep,
As from afar I watch and weep.

thanks a million