I just wanted to say that you're not wasting anyone's time. Keep posting. You're not alone. And we don't mind hearing about your problems. Sometimes it's nice to just be heard and not judged. And that's exactly what PC is for.
I also wanted to tell you that I suffer from depression and I also have no "visible" reasons to feel the way I do. I wasn't abused, my parents didn't divorce, I never had any major problems in my life. But I'm depressed. And I do struggle with the guilt for "not having an excuse" to feel the way I do. But I work with a therapist, and she's been very helpful with working on turning my negative thoughts into positive ones and not beating up on my self. Don't be ashamed to look for help -- there is no shame in it.
You're not alone