If you are to live together like that because of financial constraints, the best thing to do would be to sit down and have a talk about how you can make life easier for eachother without trying to think that "You want to make it work." It sounds like this is not something she wants, and it's stressful knowing that you do want it. It's a messed up situation, and similar to one i've actually been in myself - and we had hte talk, slept apart, and I quickly got the money i needed together to get out and into my own place.
Between those times, it was tough - but leading up to me moving out, because of the non-pressure by eachother to discuss making it work, and accepting things for what they were (completely over) we were actually hanging out as friends towards teh end, and it was... i wont say fine.... it was weird, but it was civil. The mourning was kind of put on hold, so to speak, which I know is unhealthy, but if it's your only option see for the sake of everyones sanity if you can't revert to being like roommates until you have to move.