No one is worthless. Everyone has the potential to make a positive impact, via work, volunteering, activism, or even simply being nice and friendly to people.
Studies show that being nice to people helps make you happier. https://www.today.com/kindness/secret-happiness-acts-kindness-says-new-study-t30021
"Two recent studies suggest that giving to others makes us happy, even happier than spending on ourselves. What’s more, our kindness might create a virtuous cycle that promotes lasting happiness and altruism."
Studies show that volunteering can help lessen depression and even extend your life. https://www.everydayhealth.com/depression/how-volunteering-can-lessen-depression-and-extend-your-life.aspx
These benefits are on top of the fact that you're bringing joy and hope to others, and the happiness & sense of purpose that can come with that.
If you’re depressed then I understand that it can be difficult to even get out of bed to do any of those things, but your existence is still preferable to nonexistence, because one day you’ll probably be able to get out of bed, and then you’ll be able to make those positive changes. If you didn’t exist, there would be no such potential.
Keep living. You're here, and you have the ability to make a positive impact.