Hello and welcome. If only we could all be content with what we have, but we are so often not satisfied or even content. It is a problem I think everyone has from time to time. Not much help at the moment I know.
Again we all have thoughts about being worthless. We are human and we mess up now and again. I know when I remember something I wish I had done differently I feel dreadful, so annoyed with myself over and over. It's not a good place to be. I also get to the point of despair at times. I have various coping strategies which I should put into operation, and usually do, but there are times....
I very much doubt your thoughts reflect the whole of your life. As you have posted in the Depression forum I presume you have depression. It's not a good place to make decisions as your view of the world is not clear. This is reflected in your thinking and I can most definitely relate to this. When we are a bit down the black dog comes calling and often finds a hole to get in.
So what to do. It would be good if I had more information about you to make suitable comments. Are you adult/male/female/general age group? Do you get counselling about your depression? Posting in here is a good move as various people will respond though it may not be until the morning. Most folk are in bed at this time.
Can you talk about the thoughts in general, how they make you feel and are you tempted to harm yourself? Did it help to write in here? This is a good place to unload your backpack and chat a while.
I think some of us would still be discontented no matter how much we had. Instead of trying to shut out the noise etc from your brain, which rarely works, get up and make the decision to do something. Wash the dishes, weed the garden, go for a walk, go to the gym or any other activity. Physical because you need to use more brain power to work hard. The brain is a bit lazy at times and when everything goes pear-shaped, My friends and me are ablest to handed to us on a plan.
Take heart. Do you chat with your GP about these things? They are usually happy to do this. I think it would be worthwhile. if only to reassure you.
This is just a quick note to welcome you. I must go to bed as I am falling asleep as I type.
Hope your chats go OK.