Oh What to do...

I'm posting here because I am having trouble deciding what i want to do career wise. I am a new grad and have been at my position within a critical care department for about 7 months now. I signed a contract to stay with my hospital for a couple of years and was picked out of many to get this job. However, the stress and the lack of sleep/eating has caused me to feel both sick mentally and physically (totally miserable!). To boot I moved for this job and am missing my home base. I took some time off from work and am now considering to give my notice once i go back. I feel odd about giving notice because i was one of the few selected but at the same time, i feel myself getting sicker.

Here are my concerns: 1.) Is it advisible to resign and break my contract? (Granted I believe i will have to pay penalties) 2.) Will i ever find a job path? (I say this in this way because the job market is so bad and am concerned that if i leave i wont find a job for a long time). 3.) What do i tell my employer as to why i'm quitting? (do I say im leaving for medical reasons? this would cause probs with other jobs..)

Any constructive feedback would be appreciated. It just makes me all nervous!