Depression is a joy sucker. It takes every insecurity and everything that isn't right in your life and magnifies it to a point where it seems like nothing but a great big disappointment. And not being in a relationship, when it seems like everyone around you is getting married, takes being alone and turns it into loneliness. The worst thing about depression is the inability to remember ever having been happy.  Which then makes the downward spiral feel inevitable.  Time for introspection is healthy.  But when you find yourself unable to do anything but stew and feel like a failure, you need to get out of your head and realize that this isn't the time to take your own inventory.  I wish there were some magical solution. Something I could say that would lift that feeling of failure and despair. But depression is like looking at the world through shit covered glasses. It does get better. Like a kaleidoscope, sometimes a simple move will change everything. Stay active.  Make the effort to hang out with friends, even when you don't feel like it. Find things to do that don't require a lot of thinking, just doing.  And keep talking to people, here, there and everywhere until you hear words that make sense to you.