You have set such a fire in me that it neither/never burns completely, nor can/will it be quenched. All it does is keep smouldering slowly and painfully (or: in slow and painful agony).
A mere suggestion, as I said. Perhaps someone else can improve it?
The same question had popped into my mind! Well, we don’t really know, do we? Anyway, bearing in mind that anything goes in poetry, the idea might not be so incongruous after all.