TW Anxiety, family death

My grandmother has been hinting to my mom that she is very sad that she hasn't seen the peep in about a month. She keeps telling my mom that she wishes she were a more confident driver because she would drive herself the hour and a half to our house (bad idea). So I called her this week hoping we could come see her for the day Saturday. She's spending Friday with her boyfriend and has a sleep study on Saturday so we set up getting together the following Saturday. I keep having this horrible, obsessive thought that she is going to die before she gets to see the peep again. I don't know why. My grandmother is 81 and a diabetic, so we're no stranger to health scares. Ever since she got an insulin pump a few years ago, she has been much better at managing her diabetes so I really have no reason to believe she is going to keel over any time in the near future. I'm at a loss of what to do about this. I mean I'm a worrier to begin with but I can handle having the thought of dealing with crowds at the grocery store hanging over my head for the day. This? This is torture.