What Causes Loss Of Appetite?

HI, I havent been eating alot the past couple months and i used to eat a lot... 3 meal s a day maybe a healthy snack or too after athletic activities, but then about 4-5 months MAYBE 6 months ago i lost one of my best friends we started fighting alot we finally told each other we wernt friends any more we both started cutting ive stopped i think she has too... but a couple weeks after that my boyfriend broke up with me after we started falling apart, then i got even more sad i would sit in my room for hours every night crying sometimes i cried myself to bed. well a couple weeks ago i got my best friends back and my mom got a call apparently and she told me i couldnt be by her any more again and she doesnt like her she took my phone too... i had a friend that died last month on the 8th i havent been eating you can feel my ribs, when i take pictures with people they ask why they can feel my ribs. you can see them when i take my sweatshirt off too, am i anorexic? or depressed? please help me