Leaving Work at Work

I am a new grad and really do love my job, but maybe a little bit too much. I have been working for a little over 4 months and it is getting harder and harder for me to leave work at work. I work on a highly acute pediatric floor and on my days off, I find I am wondering how my patients are doing and if they are okay. I rehash over and over in my head things I should have done differently the day before, things I wish I had time to do but did not, and I worry about my patients who are chronically ill. I rarely take breaks at work because I find myself worrying about my patients, I'd much rather just eat at the nursing station and do paperwork at the same time. The funny thing is that when I am actually at work I never feel bothered by anything, it is when I get home and have time to sit down and think that I begin to feel upset. On my days off, I find myself thinking so much about work that I wish I was there. Everyone tells me that I am going to get burnt out if I continue the way I am going, and it is probably true. I know other people have posted similar things before, but I am really struggling with this. I worry that if I get to the point where I can really leave work at work, I will no longer be warm and compassionate to my patients. How do you leave work at work without losing your compassion? Any advice will be greatly appreciated.