Is there an explanation to all of this

when i dont go out or do something during the day, i just feel down right sad. i always get nostalgic too. i used to be constantly stressed and upset and i just thought that was because i had ADD and bad grades but now im doing a lot better in school and i still feel sad. i used to always be excited to hang out with friends and make plans but now i never make plans, none of my friends make plans with me, and even i just can never think of what to do with friends because nothing appeals to me like it used to. i still always seem to look happy and i always act like im happy, and i feel like im happy, when im with my friends but then when im alone im just not. i never get excited for things anymore, i want to be but im just not. nothing has happened to me that has made me this way, so i just cant find any explanation to why im always so sad. ive also had weird changes in appetite. im always hungry but no food ever appeals to me. i just dont know what it is or what i should do about it.

You are really describing some pretty classic symptoms of depression and I'm really glad you wrote in about it. Even though it isn't a constant feeling and sometimes you feel better when you are with friends, you are describing depression and I really urge you to talk with your parents if they are supportive and tell them it isn't simply a phase and that you'd really like to see a counselor. People are always quick to assume with kids and adolescents that things are "phases" and you'll grow out of it, and you might, but if you've felt this way for longer than a few weeks, please talk with someone about it. Kids get depressed just like adults and even if it is a phase, counseling will help you through that too.