Stress, confusion, and miscommunications

Life can be so scary at times and this is one of them.  My sister needs me to help her out this summer.  If all of this would have happened last year, I would be there in a second but now since I have been diagnosed, I am scared to death.  Her transplant is happening later this month.  Mom will be coming down to help her for a while but the truth of the matter is that Mom is 78 years young and it may be too much for her.  I told her that I would help out, meaning I would come help and give Mom a break every so often but wear a mask so I wouldn't contaminate her.  Somehow, this was miscommunicated and became that I would stay with her for the two months over the summer.  Normally, I would be there and do it but now I am on immunity supressing meds that may make me a germ carrier.  I am so scared that I may give her germs.  She and I talked yesterday and I shared my concerns with her.  Honestly, if she passes because of something that I could have prevented, I would never forgive myself.  My heart says I need to help out and take over after school is out but my head says I can't take the chance of hurting her.  I don't know what to do.  My heart usually wins out over my head but I now have to take my husbands thoughts into consideration and he won't tell me.  I really feel like I am in this totally alone - not the first time I have felt this way.  Sometimes getting him to talk to me about his feelings is like pulling teeth.  Face it, I am alone in this endeavor and it is up to me to do the right thing, if I ever figure out what the right thing is.  I am sure things will be clearer after I finally get some sleep but sleep has eluded me for two nights now.  I assured my sister that we will figure it out and she doesn't have to worry about it.  I tried out for a show for this summer (before I knew what was happening with the transplant and such) and got a minor part but will most likely have to back out of the show with all of this happening, so I guess I will call the director tonight.  I am sure they will understand but I hope they don't hold it against me.  I had better get going as I need to collect my thoughts before I get to school.