I would say it is hard to rely on sound alone to bring across feelings like futility and hopelessness. Sometimes it can work if you try to imagine what the character you're depicting is hearing. You can emphasize the sounds which will make the main character feel vulnerable, the sounds which make him/her afraid or makes him/her think of unobtainable things.
You can also depict reality and make it really dull and grey.
Last year I made a prison film which had a strong sense of futility and hopelessness. It started bad and just got worse....
We created a strong sense of reality by recording a lot of extra voices for off screen sounds when the main character was in his cell. We tried hard to make everything sound as real as possible - but at certain moments we played pretty violent drones or sucked out all of the energy of the sound track by burying everything in a low pass filter and low levels.
As you are going to record the sounds on set, you may be getting a good feel of what the director is trying to get in terms of feelings. You can try to remember that feeling for when you are doing the sound design.
You can also try to record the sounds on set or just around you, which give you a bit of the feeling you are looking for. And when the time comes, you can try to use them as a basis for some of your sound design.