There are several unrelated songs that go by this name (among others) but Keelaghan recorded an arrangement of the Copper Family version. That being the case, the relevant DT file is

CONSTANT LOVERS

The words there are transcribed from a recording by Martyn-Wyndham Read, but again it's the Copper set. They themselves have used several different titles for it over the years. Incidentally, you should disregard the comment quoted from Paul Adams there to the effect that Frank Purslow considered this an Irish song; that was a misunderstanding of somebody's, based on a confusion with a different song sometimes sharing the title. Frank didn't think this song Irish - it isn't, though of course versions have been found there.

OH MY LOVE IS GONE (Sussex)  also derives from the Copper Family set, though in this case a little altered by Cyril Tawney.

Number 466 in the Roud Folksong Index; Laws K18. For links to various past discussions here, see thread  music to song: Constant Lovers.  Includes a couple of ABCs: neither is quite right, but the first is the better of the two. There are suggested 'chords' in another thread mentioned there, but they are for an American form of the song and probably wouldn't suit. Note also that I was wrong in saying in that thread that there is any connection with 'Stow Brow' (Roud 185) - I was getting confused by the multiplicity of different song names myself at that point.