Personally I have had more success with NEGATIVE 30 day challenges, than positive 30 day challenges, for this very reason. A negative 30 day challenge is when I don't do something every day, for 30 days. One habit might be not drinking any soda for 30 days. Then you might add not eating any fast food or pizza for 30 days.
Once I stopped medicating myself with food and weed, my true emotions surfaced and it became easier to know when I was deceiving myself. For example, when I am goofing off more than I should, I now feel sad and pained (not guilty), and consequently correct my behavior.
I second the idea of not drinking soda for 30 days. That stuff is unhealthy in various ways, and after a couple weeks, you won't miss it. It's a clear easy win. I did this in high school and have not regretted it.
Once I stopped medicating myself with food and weed, my true emotions surfaced and it became easier to know when I was deceiving myself. For example, when I am goofing off more than I should, I now feel sad and pained (not guilty), and consequently correct my behavior.