Why is it that, generally speaking, it's easier to do things when they are "for God" instead of "for ourselves".
See, I've always mocked people who give up stupid things for lint - until this year. I remember a girl in college who gave up painting her toe nails. To her - it was an unbearably huge sacrifice. Well, this year, I decided to give up sweets - the unnecessary and unhealthy kind. So - no candy, cookies, cakes, etc. For me, it's hard because I used to eat them daily. I couldn't give them up as part of my hope to have a healthier diet. So, I do it for God so there's not an option.
So, I encourage you to change your attitude about something you are failing at - and do it for God - dedicate it to him.