How do I deal with things at home?

Everything just seems so different since my dad died two months ago. I can't say I'm exactly over it, and things just aren't normal anymore. I can't really explain it. I kinda feel like a piece of me is missing. It's like I'm not me anymore. It's like everything feels surreal and as if I'm living in a fake world. Things have changed and I don't do well with change. I can't get past things. Lately I've been getting into lots of arguments with my mom and sisters. And afterward I end up going to my room, laying on my bed and thinking, "If dad was here things would not be like this." And it's like everything is so hectic in my house. And everything feels so different. Nothing is normal anymore. I'm trying to move on but I can't. It's just like I've acted like everything was okay for so long that I can't show my true self and true feelings. My friends don't even know about my dad yet, and school starts in 5 days. I feel like talking to them about it would make things better. But I also know there is a huge possibility I will just break down.