I have been through similar kind of situation before. My dad got cancer when I was in grade 9, this whole thing just suddenly happen, my mom was having depression and i got 2 little sisters to care about. Spending more time with your dad can help, since you can spend more time taking care of him and share each other's feeling. Also, talk about your anxiety with more people can also give you different point of view. Talk to friends, someone you know, psychologist, the more you share you feeling, the better you feel because we always think to worse situation when we were alone. Don't forget people in this forum will always support you.