This text comes from Catholic Hymns (1860), a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
If e'er my heart in riper years
Shall beat with anguish, grief, or fears,
My Jesus He will hear each moan,
And gently say, "Thou'rt not alone."
Though fled were every earthly friend
On whom I might or could depend
Though left by all, to all unknown,
He still will say, "Thou'rt not alone."
Though cherish'd ones around me die,
And sever'd be each earthly tie;
I still may seek my Saviour's throne,
And hear Him say, "Thou'rt not alone."
So too, when all my years are past,
And life her race hath run at last,
My God, Thou wilt not me disown,
To whom Thou saidst, "Thou'rt not alone."