I bet most people here feel like failures - I mean, why would you be on a self improvement imageboard if you were already self-improving at the level you wanted?
We come here because we feel like we're not achieving what we want to. But the truth is, many here are already doing great.
Even just by posting here and keeping 'self improvement' at the forefront of your mind, you are doing far more than the average person.
I've tried to quit junk food, take gym seriously, and gain perfect discipline for many years now, and every time I have ultimately given up and gone back to my degenerate ways… but one thing still gives me strength.
Every time I try, and fail, I get a bit further, and do a bit better than the last. Every time I try to become my ultimate self, I get closer.
If that isn't motivating, I don't know what is.
Look at the person you were, and appreciate how far you have already come.
Every failure is just another opportunity for success.
Every day is a new day.