Yes, depression is very serious. I hear that you are in pain. Is there anything or anyone that keeps you here? For me, it's my grandchildren and never wanting to hurt my children, my friends who care about me. I hate when they use guilt on me, when they suspect I'm sinking, but it's true that it is often the only weapon they have, so I don't get truly angry.
I have treatment resistant depression and I'm bipolar. I can also be manic at the same time as being depressed. I have two aunts who were bipolar and my daughter is, so yes, genetics can play a role, just as i feel certain that life circumstances also play a huge role. My hope for you is that you have support, medical care, people who love you. I am sad that you are in this desolate place and I hope that speaking about it openly will help take down the volume a bit. It can. Keep reaching out, okay, people here really do care.