Depending on the content of your lease, you may be able to leave without liability to anybody except the other people on the lease. From your question, it sounds like the lease is to "A, B and C for one year." If B leaves, then A and C are still responsible to the landlord, but they could sue B for B's share. If A is threatening B, then it seems unlikely that a court would have much sympathy for A's lawsuit. And C, your husband, isn't likely to sue you, is he?
Of course, I'm sure you've left out some details from your question, and they may make an enormous difference. Your best bet is to consult an Oregon lawyer (make sure to have your lease and any other written documents available for review).