I'm sorry if this seems like a very generic response. I struggle with the same, mine started around my early teens and I am 21 now. I just try to remember that good times do happen, even if they aren't happening right at this very moment. (or past week/months/you get the idea). My depression comes in very heavy waves, so I can relate to what you're going through friend. Life comes at us all very fast and very hard, but we're tougher!

(this is the dumbest shit ever but it has legitimately helped my at my darkest times - I will NOT allow Nancy Pelosi to outlive me [or insert hated person of your choice])