You
can handle this. Hopefully they caught your sister's cancer early; if they did, she will be OK. My mom had cervical cancer, so I know exactly how you feel...it's totally scary. Not being told what was up would bother me, too, but I think
justamom has it right, they probably didn't tell you out of concern for you and not wanting you to worry. It will be all right in the end, I'm sure, even though it may not seem that way right now.