Hopefull,
I don't know if this is relevant to you, but since in Sefira this is the week of "Hod" (Thanksgiving) I'll try to explain why Hod is essential to Shmiras Habris. I had to learn about this myself because years ago Harav Yitzchak Ginsburgh from Gal Einai told me personally that I need to work on improving my midda of Hod to succeed in Shmiras Habris.
First, some Kabbalah 101: Netzach (translated as victory, endurance, and eternity) and Hod combine to form "Yesod". In the human body Netzach is represented by the right leg, Hod is the left leg, and Yesod is the Bris.
Netzach is the ability to overcome adversity, including our challenges to be shomer the Bris. But Hod is needed to keep the Netzach going, like the left leg supports the body when the right leg takes a step. This is because Netzach runs out of steam without Hod. We reach a point when we say, "I've done enough, I've fought the battle enough, I've climbed enough, now it's okay to surrender tonight." Hod means we thank Hashem for all the blessings we have in life and acknowledge that all we have is from him, including thanking Hashem for helping us to climb in our past. This gives us the renewed spiritual energy for more Netzach. And we continue to advance, like our two legs walking together a step at a time.
So now when I start to feel that I've done enough for Hashem and "Hashem owes me" in the cosmic scorecard between me and him, I work on Hod and that helps to bring me down from my ridiculously stupid perch.