Sorry man... I know this well.
My wife has had breast cancer two times and skin cancer once. Lost my sister to ovarian, and my Dad to lung cancer (he would have told anyone it was his fault for smoking like a chimney). Never the less... its a huge burden on the patients as well as the care-givers. My wife is tough as nails, sweet as pie. She is a role-model for me... not sure I would have handled all of the poking, prodding, cutting, and reconstruction even remotely as well as she has.
Its weird living with it. Its always there... I remember when she had breast cancer the first time at 35 yrs.... we got through it and thought... "I wonder when it's coming back?" Sure as shit it came back when she was 50.
So its a burden you learn to live with as a survivor and care-giver... so yeah it sucks. You just can't look back too often, always look ahead. Its cliche but you have to look at every day as a gift... try not to let petty crap influence your life. Look to things that bring each other joy... and laugh as much as possible.
Take care.. chin up!