I'm so worried!! Need advice??!?

At the moment I'm living with my mum and my sister and my dad is living in China, because hes teaching english but now he doesn't want to come back and hes making it seem like it is our fault. I'm actually really close to my dad but because we hardly ever speak now I'm finding it really hard to talk to him. At the moment my mum feels really down and they just don't talk hardly and I'm getting really bad tension because it stresses me out so much. I think about it all the time and life just doesn't seem normal and I can't sleep properly. I find just getting through the day an effort because I know my dad doesn't want to be with us anymore, although I know he does but hes just escaping. I just don't know how to feel anymore and I just start to think I'm going crazy..I know this sounds stupid but this has been going on for years now that I just can't take it anymore but I don't know what to do....It's also lead on to me being obsessed with my weight...consequently I don't eat properly and my back is just so tense with anxiety.