Here is an exercise I am working on lately. When things seem less than favorable, there are three basic thoughts that cultivate a positive outlook.
1. I have hope...(...in God...that all will be well...etc.) No matter how adverse circumstances look at the moment, I can and I do have hope.
2. I have already accomplished...(...list the things that I've done that I didn't think I could do) When I have to do something that I don't feel I can do, I have to remind myself of all the things I've done that seemed insurmountable to me before I did them, e.g., birth to a baby, cooking a meal with no idea of how many guests would be arriving, raising six children, re-entering college after 30 years, etc. These accomplishments serve as reminders and my outlook changes from uncertainty to focused purpose.
3. I am thankful for...(...list anything I can be truly thankful for at the moment) Reminding myself of all the things I do have, helps me put in perspective my desires for what I don't have. Thankfulness protects me when I become discontent. Whatever I can be thankful for today, will keep me 'in today', enjoying all that is available to me in the present.