How to say my eternal angel in latin?

I'm getting a new tattoo and I want the words "My eternal angel" in latin. Can anyone please tell me the correct spelling? Thank you so much

The nominative case form is "angelus aeternus meus", though if you want to say "to my eternal angel" or "for my eternal angel", you'll want the dative case: "angelo aeterno meo". And if you want to address your eternal angel, you'll want the vocative case: "(o) mi angele aeterne!"

You won't want the nominative case, unless you want "angelus aeternus meus" to be either the subject of a sentence or a caption describing a picture of your perfect angel.