My verse in Swedish

Thank you very much! But is it possible to write 
Du är min bästa kvinnan?

OK

This is in English

You are my best woman,
You are always in my heart
You are my best memory
You are my greatest pain

I meant that she is the best of all women which I knew.

Thank you very much for you explanations! I plan to publish a book with my verses in Russian and thought to include this verse also, with translation and transcription. 

I have still a question what phrase is correct:

Du är min bästa kvinna

or

Du är min bästa kvinnan?

Concerning this verse, I would like to explain that this verse is about one women who was in the past with the author, but later she decided to choice another man as a husband. It was many years ago. But the author still remember her and has expressed his sence in the verse. 

Taking into account your message, I conclude, that "kvinnan" is better than "kvinna".

Concerning possessive and creepy... I do not think that possessive, but agree that this verse is very sad. When I wrote it, I remember Minnet by Dan Andersson.

The problem is: when you are young - you have not experience and can make wrong decision. But when you meet your first love after many years then both have families and children and nothing could be changed.