When I catch myself driving aggressively, I have to stop myself and say: what if my teacher saw this? What would she say? I could hear Mokshapriya saying to me: "you're not present." And what if my students saw this? Is this not what I teach and talk about in class? (And as a side-note to students: our work is all the same. Your teachers are not infallible or perfect. For everyone, the work is about being present, being focused, being mindful.)
So what is it for you? Is there someone or something that inspires you to be better? A parent, a child, a sibling, friend, a lover, a teacher, a student...? If not someone, is there a goal, a higher purpose, a challenge, a path, that motivates you and inspires you to be who you are/who you want to be?
Figure out what that this is, and use it. In your darkest, ugliest, most humiliating, mortifying, unproud moments, remember that person, that thing, that idea, that image, and let it drive you to rise to the occasion. Let it be the thing that allows you to show up, to pull through, and rise above being someone you don't want to be. Because every single one of us is that person on occasion. Every single person does or says or just thinks something that he would rather not, something that is in stark discrepancy with what she really wants out of life or out of herself.