。
What I'm hoping for is to end this unhappy relationship between us.
Literal
We [of-の] unhappy relationship [object-を] end [into-に] want-to-make [quotative-と] I [topic-は] hoping-am [explanatory-のです].
A formal sentence with multiple layers. 終わりにする ('to bring to an end, to make over') — 終わり as a noun + にする. ~たいと望む ('to wish to [verb]') is a doubled desire construction — 望む ('to hope, to wish') layered onto ~たい. The final のです is the formal/polite ~んです, elevating the register. Despite 僕 being casual, the rest is solemn.