Hi Tinker77,

Being a cancer patient does not excuse a person from bad behavior. It sounds like your sister has an aggressive personality and having cancer hasn't changed that, it's probably made her worse. She should be thankful that she has a caring sister who is helping so much whilst also supporting other family members. 

I'm from a small family and my only aunt & I fell out for 10 years because she disapproved of my husband (he was suffering from an illness but she thought he was swinging the lead). She had never ailed anything in her life so she couldn't comprehend how ill anyone could be, including my dad with a brain tumour and me with cancer. 10 years later she was diagnosed with bowel cancer at age 80. I visited her & I was astounded when she apologized for her behaviour (she'd never apologised in her life). We had an uneasy truce & I helped her and my uncle but she never thanked anyone for any help she received for the next 18 months until she passed away. I put up with it because I knew she would never change (I learned a lot about her younger days in that time) and I only did it for my poor uncle who was run ragged & who I loved and respected. 

I think, for your own well being & that of your husband, you need to put your cards on the table with your sister & give her an ultimatum. Kindly but firmly tell her that you are sorry she is a terminal cancer patient and you are happy to continue helping her but only if her attitude towards you changes. Tell her you do this because you are a loving sister, not a skivvy and a punchbag for all her anger & complaints. Say that you understand she may be acting like this because she's angry at the cancer, not at you, but if that's the case she needs to seek counselling. Finish by saying that if she doesn't agree to change, you can no longer help her except in an emergency. 

Also, if she has a son, why can't he step up & help do most of these chores? Does he keep his distance because she is nasty to him too? Your health & mental wellbeing is just as important as hers - if you became ill she would be left with no help. It may seem harsh but you have a family and yourself to take care of - you do not need or deserve this stress.

Good luck & I hope she sees sense but if not, stick to your guns. 

Angie (Stage 3 melanoma patient since 2009)