Can y’all feel my pain?

Life what the f*ck is it about cause I truly don’t know anymore. I mean nothing makes sense anymore. People tell you bad situations don’t last long but I would like to challenge that theory. Happiness doesn’t last long so if you ever achieve it cherish it because it’s temporary. However, misery can last a life time. I’m living proof of that I know I’m only 19 but I’ve been miserable for the majority of my life. And right now I’m just exhausted. My life has no meaning to me anymore. I have to be the loneliest teenager in the world. You know people think that they’re invincible until something hits them and brings them to the realization that they’re ordinary and they’re not exempt from f^cked up things happening to them. I guess that old corny a** saying is true “You don’t know what you’ve got till it’s gone.” I miss the simple things in life like friends, family, waking up in the morning and actually wanting to be alive life is just hard for me and sh*t will never get better. I think I’m in the right place to vent my feelings. Can somebody please loan me a gun? I want to sleep for eternity.
P.S. You ever know what it’s like to die while you’re still alive? Or do you know what it’s like to completely disappear like you don’t even exist?