Unhealthy Time

I have finally come to the conclusion that whenever I spend alot of time with Mike, my resolve weakens. In the past, when I have spent 12 hour days with Mike in the hospital and when I recently cared for him myself for 5 days last week, I become paranoid and fearful. I notice every single breath, gulp and movement. With nothing else to do, but focus all my attention on Mike, I dwell on his condition constantly. Is he breathing too fast? Is he breathing too slow? Is he coughing more than usual? Does he have a fever? Is his chest congested? Is he wheezing? Spending the entire day and night with Mike is unhealthy for me. Does that sound bad?
Normally, I am with Mike at night and in the morning. Then I leave for work (and/or errands on the weekends). While I see him on the weekends, I am in and out all day. On days that I work, I see him again when I get home and I help get him into bed at night. As sad as it is for me to admit, it's healthier for me this way. Maybe that's another reason why I get so concerned about Mike's aid leaving. I have finaly realized that it's difficult- physically and emotionally - for me to be with Mike 12 hours a day.
It's usually after these periods when I begin to question his health. It's at these times when I get concerned about his decline. I dwell on this so much that it's unhealthy. I tell myself that we've been down this road before and everything has always turned out OK. I guess my fear is for the day when it's NOT OK anymore. It's going to happen one day. Will I be prepared?