got written up for attitude please help

I just started a job and 2 months in I've gotten written up for attitude. I'm front desk/security at a nursing home and work with caregivers and nurses daily. It's my job to make sure the residents are being taken care of and call when their buttons are on longer than 30 min. I also have to be super nice to family members visiting and stuff (that's fine) but I have gotten stressed at times. There is a lot of responsibility in my position and I work with a new girl and sometimes she's gone from the front desk for over an hour and i have to do everything so I have come across as rude. I don't mean it sometimes but my attitude has gotten me in trouble all my life and I don't want to lose my job over it. Please help I have no one to talk to right now my boyfriend is a boot camp and I have no friends to call.