How we cite our quotes: All quotations are from Titanic.
Quote #1
ROSE: It was the ship of dreams to everyone else. To me, it was a slave ship, taking me back to America in chains.
Obviously, this is a pretty over-the-top claim, since she's not being physically confined, whipped, or starved. However, it does speak to how completely trapped and helpless she felt to get out of her engagement to Cal.
Quote #2
ROSE: It was everything. It was my whole world and all the people in it. And the inertia of my life. Plunging ahead and me powerless to stop it.
Rose is trying to explain to Jack why she was miserable enough to consider suicide. Apparently, she feels like she's just kind of being propelled toward a fate she doesn't like without any power to stop herself.