gnome01,
I'm not a psychologist and I'm not well versed in depression except for what I've read and from people I know who've suffered from depression. I can, however, speak to the times I've messed up...and in a way, I think you feel that you messed up by being depressed.
My basic philosophy on mistakes is pretty simple. Learn from your mistakes and move on. As they say, "It is what it is". You can't go back in time to change anything. You may not have taken responsibility for your actions in the past but guess what? You can take responsibility now! You have a choice...
1. Feel guilty, don't forgive yourself and perhaps slip into another depession,
or
2. Forgive yourself, try to identify why you were depressed so you know the triggers to avoid it from happening again, and move on. Choose to live now and move on with your life.
You're at a fork in the road...follow choice #1 and you'll likely be posting a similar post 5 years from now. Choose #2 and you write a new story for yourself.
I know that this is easier said than done. But take some time tonight and meditate on both choices. I advocate you select #2 (obviously).
In my experience, what will help you is being actionable toward your life purpose. Read
Steve's article for more info.
If your depression was serious (suicidal thoughts, etc.), you my want to get help in this effort to forgive yourself and move forward.
Good luck.