What to do when your new job is still stressing you out 5months down the line?

Last october 2009, i took a new job as a manager of a care home for the elderley. Previous to that i worked as a co-ordinaot arranging care within the community. I wanted to take a management position as i found the co-ordinators position was not testing me and i felt i was not using any part of the business studies degree i had acquired. Now i took a new job as a manager which is my first management role. I am a strong individual, who gets on with all types of personalities. However i am finding this role really stressful. The staff got used to not having a manager as my predecessor had left 8 months before i started. So i have got a load of staff who are used doing what they want and are 3 times my age. I have got loads of work to pick up from what the old manager didnt do, so i have got to mop all of this up. Coupled with how big the job role is i have to keep disciplining staff who are making errors. I want to succeed for the service users the elderly, but at the moment work is all i can think about and its getting me down. Can anyone give me some advice??