Meus amor tui perpetuo permanebit (or maybe the present permanet would sound a a little better). I think there are multiple ways to express this, but you definitely need an objective genitive with amor.
I also want to translate this into Latin.
You’re no one’s queen but mine.
Here’s my translation, but I feel that I may be wrong:
Regina neminis nisi mea es.
My first guess was to use > sed > instead of > nisi> . Am I right in saying that that sentence wouldn’t make sense if I used > sed > instead of > nisi> ?
Nisi works nicely. But here I want to use the dative, nemini and mihi, “you are queen to no one except to me.”