Just want to leave this all behind

I am in fear of what i am capable of doing. I can not seem to get out of this darkness no matter how many times i tell myself, head up this too shall pass. I sit at my desk at work at a job i am fear of comign to every day and i break down in tears. And they just keep falling. People around me dont understand they tell me "just deal with it" or "get over it" makes me feel like no one cares. Like no one would care if was gone. I see friends or ex lovers happy and living an amazing life, getting engaged, married having kids and wonder what was wrong with me that i couldnt have all that? i know i am feeling sorry for myself and there are worse off then me but i just dont feel like that is the truth. I have come a long way from where i was 20 + years ago yes and i am proud but these days i wish i would of just stayed in that darkness cause it feels like nothing has changed.