Hey, PG. :hug: I'm sorry that you've experienced a tragedy so close to home and I'm sorry you're feeling that you are useless and a failure.
We are often our own worst critics. We fault ourselves for things we would forgive in other people.
You say you are failing at everything. I believe that in spite of your negative self-assessment, you have a lot to offer the world. I see a sensitive person who is obviously intelligent and who cares about what is happening to his/her friends who are now mourning. That is certainly not failing. What else is happening in your life? Are there other specific things that are bringing you down? Feel free to share if you want to. This is a good place to air our thoughts and feelings.
Stay safe and take care.