Daughter Angry at Parents' Secret

QUESTION: A few years ago, my dad was diagnosed with a fatal degenerative disease. My parents moved down South because the warmer climate helps dad's condition. Mom takes care of him, and every second of the day, she's very stressed.

My siblings and I live in the Northeast and don't get to see them as often as we'd like.

A year before dad got sick, my parents seemed to go through a positive midlife crisis. They lost weight, found new friends, and partied every night. They rarely saw us or talked with us because they were busy. They seemed to be enjoying the next stage of their life together. If I complained, they said they were "having a life now" because raising kids had taken all their time.

My brother recently confided to me my parents were sowing their wild oats then because dad knew he was getting sick. He knew he was on borrowed time, and he'd have to sell his business and give up driving. He told no one but mother.

I am extremely upset with my parents. While they were going out every night, we could have shared some time with him before it was too late. Although I cry every time I see dad, I feel I maybe don't have as much sympathy as I should. Knowing he kept a secret like that has altered our relationship. When mom calls and complains that she has no life and has to do everything by herself, I want to say she did it to herself. My siblings and I are not selfish. We would have done everything for our father.

Please tell me if I'm being overly emotional. Didn't I have the right to know? Am I entitled to be angry, or should I let it go?