How to deal with different types of depression

I.. I don’t like claiming that; I’m not medically diagnosed and I don’t like thinking of the possibility. I’m going into my junior year (high school) and my siblings are leaving soon. My sister and I are best friends and it’s unbelievably difficult to be apart from her, 1000 miles away. My brother and I have a lot of fun together and there’s no one else really like him.. it’s the second year I’ve been alone at home but with school starting and everything I’m just so so afraid. School is always too stressful, and I never have time to do anything I enjoy with all the work which makes everything infinitely harder. My mum stays at home and I wish I had a better relationship with her, but as much as I try it never ends up quite right. And then fall comes and that hopeless feeling hits, like going on isn’t worth it, and I just feel stuck. It’s so hard, so so hard. I’m scared for what’s coming because I know what happens to me and I hate it. I have nothing, I lose my personality, my motivation, I lose myself. I don’t know how to deal with it. I just want to move back home but it’s not possible with my dad’s job. I just don’t know. The overcast skies and cold hit harder than they should.