Help I guess

My dad is upset because of tax coming in late. He expects me to be the adult when I'm only 17, I can't keep doing this anymore it's too much. I can't do the things they aren't my problem, he constantly uses the words "my mom is dead and I have no one to help me" and it constantly makes me feel like I'm nothing. I get that she died but it's been 4 years and I hate hearing it over and over again having it make me feel awful.