Oh pit of debris, fierce cave of the shipwrecked. (6)
The woman is described as a cave where hapless, shipwrecked sailors ended up. She's like the ultimate destination for foolhardy voyagers, and you can count our speaker among them.
turbulent drunkenness of love, in you everything sank! (14)
The comparison of the woman to the sea, which swallows up everything, is paired with the reason for their shipwreck: their love was wild and mad… and pretty much foolish.
Lost discoverer, in you everything sank! (18)
The speaker feels like a shipwrecked sailor, one of those brave souls who crazily went out to discover new lands and never came back. In the same way, he can never really come back from his love affair.