you do not need to be forgiven for struggling. It's just a part of life and some people are better equipped than others. Life is not cruel and almost never fair.
It may be important to you to forgive yourself, and based on this post i'd say that's likely true for you.
I would be the very definition of a hypocrite by saying but im going to anyway
The easiest way to struggle through depression and begin to forgive yourself is to simply not let the depression win.
Get out of bed, take small steps towards improvement, whatever that may mean for you. In the end it often wont matter and depression often wins but sometimes, just sometimes, getting out of bed is enough and anything beyond that is a small victory you did not know you needed.
I know it's all so cliche and yet still so true. I have been depressed long enough to know its true and long enough to know its not true so my words are worth nothing, I know.
But maybe they are worth something ya know?