Angelus curator --> Custos angelus or Angelus tutelaris
But are you sure it is in nominative here? Shouldn't be vocative?
"Anima mea cave".
Hehehe! "CAVE CANEM" = AVOID A DOG! (Literally: Beware of the dog )
So, unfortunately it is not a good word, dear Goncin. I propose: "protege" or "defende", "custode" + ACCUSATIVUS.