I think I am depressed?

lately, i have been sad. i dont like to talk to my friends or go out with them. i am moody with everybody. i found out my best friend is going to move away once her house gets sold. i have been antisocial all day and didnt feel too good. i dont have any family problems or anything. i know i dont have a good reason to be depressed or anything but i just dont feel too happy all the time. sometimes i eat a lot and sometimes i barely eat at all. i dont think thats really normal. i also feel no one likes me or cares about me and i feel i have no one. i dont know what to do. and also i dont know if im depressed. i just wanted someone elses opinion even though i didnt tell anyone.