Have you ever committed a mistake...

[saaretjie]

Promised yourself that you'd never ever do it again... and ended up doing it again?

I've done that recently and it makes me feel like complete ♥♥♥♥♥. I feel like I have no energy or purpose to go on. I feel if I can't back up my words, than I'll never amount to anything. In short I feel a deep self loathing.

And slowly instead of trying to improve, I've slipped so far backward that I would say I'm at the lowest point (in my admittedly quite happy and sheltered) life.

Has anyone else ever done something like this? I doubt it. Only I could be such a stupid schmuck.

[Ilya]

Many times.
You know as they say, saaretjie - "never say never". I know Steve is a strong advocate of making a decision and sticking with it by the sheer force of willpower and discipline. He also is an advocate of month-long trials. And as far as I understand it took some practice to be able to do both.
It is the same for me. Learning how to stick with decisions was a process for me. I think I came out of it with a set of slightly different beliefs than Steve.
Most of the time I didn't keep the word given to myself is when I was learning something difficult and was approaching it from a wrong angle.
At first I was beating myself much like you do in your post. Didn't help. Only undermined my self-esteem.
Then I've learned to use my mistakes as lessons. And failure to fix the mistake as even more important lessons. If I make one mistake, the fix is obvious. If I repeat the same mistake, then the reason for it might not be as simple as it seems.
So, stop beating yourself. Instead try to analyze what makes the behavior that you try to avoid so difficult to avoid. What good is in it. What can help you to change your behavior and so on. There were behaviors in my life that took literally years to fix and I'm not done with all of them. Does it mean that I'm weak? Not to me. In fact I'm very strong in maintaining some not very effective behaviors. But that is just a lesson I have to learn and will learn eventually. I wish you to develop some positive attitude toward your mistakes - they are just feedback and experience as they say.