I have just decided to change my nick to Gerhard, which starts with the same three letters and professes me as a German male person.

Sentimental: I see, agreed.

Woman: A mythical female being (witch, elfin, ...) like Lorelei is something else than a woman. Here she is a personification of a man's self-destructive erotic dreaming (can happen to women too). Note that the narrator is not the sailor, but someone who is haunted by that myth. He is about to become conscious of its sad meaning to him: he has to dismiss his illusions to avoid being consumed by them.

The "witch", if you attribute any reality to her at all, does nothing but comb her hair, the luring is done by the imprudent sailors themselves.

Helmine/a von Chézy, the poetess of Ach wie..., was a woman.