He'll die if he doesn't get to a hospital - due to the wound he received on the last mission with Carrie. But he knows that if he's any hospital, that will spell death for Carrie, even if the docs can help Quinn, because the bad guys will be able to trace Carrie from Quinn. Carrie's willing to take the chance, as the only alternative, however bad, to Quinn dying. Quinn isn't.
He tries to kill himself by tying himself to a brick and jumping in the water. Some guy with a beard stops him. Quinn then tries to hide himself in a dumpster. He doesn't have the strength to lift himself up, and the guy with the beard arrives to save him, though Quinn doesn't want to be saved. Who is this guy with the beard? Presumably someone not good, but you never know.
What we did know, almost from the beginning, and was confirmed last night, is that the head of the US CIA unit in Germany is the villainess - she's the one who gave Quinn the order to take out Carrie. What's still not clear is how much Saul knew about this. We can assume that he knew Quinn would never kill Carrie, so he may have been setting the CIA woman up. On the other hand, there's been no indication of this as yet.
Carrie may care about her new boyfriend, but not as much as she does for Quinn. She's willing to put her own life in jeopardy to save him. When push comes to shove, it's all Quinn. And he clearly loves her. I can only hope that they both survive this season. Carrie is clearly not expendable.
But, what about Quinn?
And see also Homeland on Showtime ... Homeland 1.8: Surprises ... Homeland Concludes First Season: Exceptional
different kind of espionage