Does this make me heart less?

Quick back story ... my dad is a dead beat. Growing up he was never around, hes an addict (alcohol and drugs). Recovering and relapsing my entire teen and adult life (I’m in my early 30s). My parents had me(I’m the oldest) and my 3 siblings before age 24. He was an abusive alcoholic to my mom, she was strong and brave enough to leave him while pregnant with my bother.

He moved to another state when my brother was 15 so he wouldn’t get arrested for not paying child support (he’s a great guy).

He finally was in recovery for almost 4 years. Still the same guy though making no effort to be apart of our lives and making it out to be our fault for not having a relationship with him.

Last year he was diagnosed with throat cancer. He relapsed and started abusing pain killers, bc he relapsed he didn’t finish his cancer treatment. he’s now in prison and the cancer is back. He recently had surgery to remove lymph nodes in hopes to decrease the risk of it spreading to his brain. I have zero emotions about the entire thing. I said to my mom that he’ll be died in a year or two either from cancer or drugs.

My sisters told me I’m being heartless, bc I’m not sad about him having cancer.