What can i do if i feel overwhelmed while taking care of my dad with cancer?

i moved into my dads house with my 2 kids and last september we found out that he has inoperable cancer. i quit my job to take care of him and have been doing so since then. i also have 2 brothers one thats incarcerated and the other lives 1 hour away. now i take my dad to dr appts. well simply everywhere. but sometimes i need to spend time with my kids or i might even want to have some me time. a couple hours thats all, but when i try my dad calls my brother and says things like i know she hates me and she wont even come to see if im dead or alive.{ just let me say this, he is not incapacitated he can still do things for himself and every morning he goes to the neighbors house and has coffee} then i get frustrated and me and my brother start yelling and agruing about the things my dad tells him. thats when my brother takes it upon himself to call this meeting between the 3 of us and makes me the bad guy. ive told him that when he starts helping me with him ,then tell me. please help!