Unseen, unknown

Here is a lyric by Lady Mary Wroth in the early 17th century. Can anyone enlighten me on the underlined lines, especially of the syntax, please?

Unseen, unknown, I here alone complain
To rocks, to hills, to meadows, and to springs,
Which can no help return to ease my pain,
But back my sorrows the sad Echo brings.
Thus still increasing are my woes to me,
Doubly resounded by that moanful voice,
Which seems to second me in misery,
And answer gives like friend of mine own choice.
Thus only she doth my companion prove,
The others silently do offer ease.
But those that grieve, a grieving note do love;
Pleasures to dying eyes bring but disease:
And such am I, who daily ending live,
Wailing a state which can no comfort give.

Unseen, unknown, I here alone complain
To rocks, to hills, to meadows, and to springs,
Which can no help return to ease my pain,
But back my sorrows the sad Echo brings.

Thus still increasing are my woes to me,
Doubly resounded by that moanful voice,
Which seems to second me in misery,
And answer gives like friend of mine own choice.
[Ie. the answer my echo gives is like the answer one of my own friends would give me – sympathising with my 'misery'.]

Thus only she doth my companion prove,
The others silently do offer ease.
But those that grieve, [do love] a grieving note;
[Ie. people who are sad and 'grieving' find comfort in listening to sad sounds or music ('grieving note[s]') because it reflects their mood.]
Pleasures to dying eyes bring but disease:

And such am I, who daily ending live,
[Ie. and so am I (sad and sorrowful) and I live like this all day.]
Wailing a state which can no comfort give.

Hope that helps.

That helps. Thank you. But still, I found the syntax difficult.