Is there something wrong with me ?

This week has been a really tough week for me, I don’t know if it's anxiety or not but I'm always not focused and I constantly  Feel dizzy when I stand and sit down. I make sure that I drink plenty of water and eat but I still feel like that I don’t know what to do? Every time I go out to school and places I feel happy but when I'm home I feel sad which I don’t know if it's because of my sister with diabetes, Dad with Post traumatic stress and the way he’s been behaving. My strong emotion of sadness is taking over and its driving me crazy and I'm not as happy as I was this year which sucks because I want to be happy. Some day's i am extremely happy and other days just so sad and I feel like I'm not copying and I want to be able to cope and everything in my life is changing so fast I can’t even control it. Why do I feel like home is the last place I want to he right now? I just feel like if I'm home with my family I get so sad but that doesn't happen every single day. I just want this to go back to normal which I know can’t happen I been copying for months with my Dad I just want him to go back to normal and I'm getting to a point where I can’t cope. Does anyone have any advice or words of wisdom cause I could really need it right now.