My heart hurts when I see posts like this because I understand what it feels like to be caught in depression and feel hopeless. You are not a lost cause. I find one thing that helps is focusing on the short term. Only look at each day. When you look ahead it becomes overwhelming. Do remind yourself of the positives, but know that it is okay to still feel sad.

Have you considered ECT or TMS as options? Some people that can get relief no other way benefit from these treatments.

Above all else, please know that you matter. I know it's hard, but you are important. I also believe it can get better and the journey will be worth it.