Just why..

I have never felt so upset and disrespected in my entire life. So with the depression I have, some days it's really hard to get out of bed. There is nothing left to your body, you lay there and sleep. So when that happens, which has unfortunately been quite a bit lately, I physically cannot go to work. I feel bad about calling in, but I try and give as much notice of my absence as possible. But today, I was feeling okay until I got to work and my mood went extremely down hill. I am in retail and I usually am on cash, so having to deal with people and feeling like crap at the same time is hard. I was planning to tell my manager today what is wrong with me and why I call in sick, but before I could, I was called into her office. She sat me down in front of a computer and said that the days marked in green were times I called in sick, that's when I said I needed to tell her something. I couldn't get it out before I started crying, but I managed to tell her my situation and how sorry I am and how much I really try to beat those days. It didn't seem to really phase her. She sounded sympathetic for a slight second and then said to me, "I need to run a business." I understand that it's hard on her and all my other managers to have to figure out what's going to happen when I can't be there and I know they depend on me. But how can someone like me, someone who hates what they see in the mirror, someone who has low self-esteem, confidence and worth and who practically cries herself to sleep every night be any more useful to people? I feel like no one will be able to depend on me in future jobs because I can't be there physically and mentally. How am I supposed to be there for my future family and kids when I get fired from jobs because there's a voice in my head who tells me that I can't and don't even bother trying because I am a worthless human being in this world? I am trying so hard! I'm taking my medication, I'm getting myself into a routine, I'm eating better, I'm exercising. I don't know what else this monster wants from me! It already has my sanity, isn't that enough?! The only reason why I haven't given it my life is because I am an only child and I couldn't do that to my parents. It would kill my mom because she's already lost her mom to Alzheimers and her father died a few years ago and her brothers because our family is broken. She has no one on her side anymore. So I couldn't do that to her, no matter how much the pain is. No matter how much it hurts. So I will keep fighting even though I don't believe I can do it, and I have already given up a long time ago. I'll keep trying for my mom and dad, because I know they really need me.