I'm depressed help me?

I think I have had a pretty bad life and it all stared when my Bff died she was 12 I was 11 and I was heart broken that's when I learned to plaster a fake smile on my face every day. I still have a fake smile on my face sometimes. But after she died I didn't go to her funeral and that was one of my worst decisions of my life. If I could go back I would go and I also didn't talk to her for a couple months before her death and if I could go back I would call her everyday and vist her often but I can't go back and I am depressed. After she died my family forced us to move causing me to pretty much lose the rest of my friends I still text them sometimes but I haven't acually seen them in 3 years even though I only live 45 minutes away. Then about a half a year after we moved my grandpas best friend who I was very close to died and I miss him so much. I had to go to his funeral and I was so sad to see him there lying dead in a casket was herat breaking and it made me think maybe if I had gone to my friends funeral it wouldn't have helped. I just graduated freshman year of highschool and nothing bad has happened to me recently I have a wonderul life and great parents and a lot of friends and a roof over my head but I'm still depressed. This story is 100 % true I didnt make up any of it and I really think I need help. I think about killing myself constantly but I can't because I can't cause my friends and family pain. I also think about becoming anorexic because I think I'm chubby even though my friends think I'm thin and one said I could be a super model I'm on a diet where I only eat meals no snacks or desserts for me and I have started eating less at meal time some days I'm so depressed I'm not even hungry my stomach doesn't even growl but I still eat cause I know bieng anorexic is wrong. Help me please!