I think I'm also struggling with feeling like I have to forgive myself, because I just should have know better. Goes to show me that I screw up - it's good for my ego. I think God (who never tempts anyone) let me see how insufficient I am by myself to be good. I have to rely on Him as I vehemently combat sin; and thank Him for His forgiveness when I fail. As I wrote in my Gawain paper, the noble are shown by how they react when they sin.
Here I am Lord and I'm drowning
In your sea of forgetfulness
The chains of yesterday surround me
I yearn for peace and rest
I don't want to end up where you found me
And it echoes in my mind
Keeps me awake tonight
I know you've cast my sins as far
As the East is from the West
And I stand before you now
As though I've never sinned but today
I feel like I'm just one mistake away
From you leaving me this way
Jesus can you show me
Just how far the East is from the West
Cause I can't bear to see the man I've been
Come rising up in me again
In the arms of your mercy I find rest
Cause you know just how far the East is from the West
From one scarred hand to the other