Roller Coaster of Emotions

My dad was diagnosed with lung cancer 2 weeks ago. Two weeks before that I accompanied him to several doctor's appointments until the cancer was diagnosed. We live two hours away from each other and he will soon begin radiation therapy M-F for six weeks and a round of chemo each week. I have siblings that live 4 hours away from him, yet only one is actively trying to help out. We both work (the other one doesn't) and are trying to coordinate our work schedules and personal lives to be there for our dad during his treatments. I have so many emotions right now and just end up crying out of the blue. I'm mostly angry at my dad for smoking, even after he was diagnosed with COPD. I'm angry that he was diagnosed almost 7 years ago, but I didn't find out until we were at the hospital waiting for his lung biopsy. Then, I feel guilty for being angry at him. I'm angry that my one sister refuses to help out, but calls me after each appointment when I'm feeling overwhelmed and am still digesting the information. I'm hurt and disappointed by friends who have dismissed my feelings with a "You're strong, you'll get through it." I was in the middle of crying on the phone last night when one friend she said she would have to call me back in a couple of hours because her company had arrived. I still haven't received that return phone call. I guess I just need to have my feeling validated. After so many years of trying to be there for other people, it hurts when it seems like no one is here for me. It's nice that my coworkers ask me how my dad is doing, but I'm affected too. I'm the one that's living between two households right now.