Forgive me the comparison, very inadequate as for the context (emotions vs economy) but love/marriage relationships are very much like the stock market. When you lose faith in the value of a share, you'd better take your losses and run.

However, coming back to true life, as long as there is still faith in a possible common future, and genuine willingness on both sides to make things work, I'd say it's worth trying. But this is all very personal.

When through hell, just keep going. W. Churchill