Please help with this...............?

If you leave a mental illness untreated, i.e try and work through it yourself, what do you think the long term consequences would be? Could it get worse? I'm pretty sure I have depression and I have lost all self-respect and worth. I havent actually told anyone though as even though I feel really close to the edge sometimes, I dont want to dump these problems on anyone else. I think it is getting worse. thanks in advance