This is from the Ohr Someyach, Hilchos Talmud Torah.
The difference may be subtle, but it can have an enormous effect on your attitude towards your obligations – If we realize that our personal difficulties with our obligations will not only be taken into account at Judgement Day, but that Hashem originally, in the Torah, only asked of me what He feels I can do today, we would act differently.
This is also a thought which allows you to have regret, but not guilt – After all, today that I must do Teshuvah, this is what He wants from me now – what He wanted yesterday is irrelevant!
I’m working here with the premise that your being honest, not just bashing yourself as a way of making a point (though you’re certainly doing that as well!)