I remember when I was 14, I used to act all "cold and mysterious" at school and pretend nothing made me happy because I wanted to be some sort of teen fiction protagonist.  
Now I'm twenty-one and I get really bad bouts of depression. I hyperfixate, I spiral until I get headaches and panic attacks and convince myself I'm useless and will die alone and unloved. I overeat and undereat and being alive or doing work or trying to commit to hobbies just feels like a damn chore. I wish I hadn't faked it back then - the real thing is debilitating and being happy, or feeling like you at least deserve to be, is genuinely so difficult. I'm surrounded by people who claim to love me and I'm in a healthy relationship, and yet all I feel is a sense of loneliness and constantly wanting to disappear.  
This shit is so  mentally draining and I don't know for how much longer I'm supposed to live with this. I'm tired. Someone please tell me it gets better :(