Oh, I know it's traditional; I used to sing the Copper set myself, though I knew it as My Love has Gone.  I thought Joe was talking about another song of the same name, but if I'd translated the abc at the time, I'd have realised it was The Drowned Lover again.  Still found in tradition, particularly in Southern England, incidentally, and sometimes linked with Stowbrow (near Whitby in Yorkshire), though its real history is probably more complicated.  There are several texts in the DT, under various titles, beside the Constant Lovers (not its usual name) linked to above; the English ones don't differ a great deal.  Laws gave it his number K18, and it's number 185 in Steve Roud's Folksong Index.

THE FORSAKEN MERMAID  From the Copper Family Songbook, with tune.

I NEVER WILL MARRY  From the Weavers (at one remove), though with no indication of their source; reference is made to an earlier recording by Texas Gladden of a different version.  Two tunes are given; presumably the first is the one used by the Weavers, but the second is a puzzle; perhaps it was Gladden's?

OH MY LOVE IS GONE (Sussex)  A text harvested from the Forum, apparently learned from Cyril Tawney with only a few very small differences from the Copper Family set.  No tune given, but it will be the same as theirs.

In the Forum:  lyrics:I Never Will Marry  Two texts, one with suggested chords.  No indication as to the source of either.

There are several broadside copies at  Bodleian Library Broadside Ballads;  here is one:

The lover's lament for her sailor  Printed c.1840 by W. & T. Fordyce, Printers, 48, Dean street, Newcastle.

There are even more examples there of the other Constant Lovers that I referred to (Laws 041, Roud 993), mostly of the early-to-mid 19th Century; such as:

The constant lovers  Printed between 1819 and 1844 by J. Pitts, Printer, Toy and Marble warehouse, 6, Great St. Andrew Street, Seven Dials [London].

There is also what may be an earlier and much longer version,  The Goodhurst garland. In three parts  Date unknown; "printed and Sold in Aldermary Church Yard, London".