Превод - Руски-Английски - Милая

Dear expert,

I think it's important to preserve not only the meaning but the impression this request makes.

It's very beautiful, "warm" and touching in Russian.

So may be I'd translate it like this:

"Sweetheart, my darling, (you are) my cradle and a grave to me... My beloved wife* (...) and have mercy on me."

* mistake in the translation as it's not my wife and my beloved but my beloved wife.