Practice choosing discomfort.
Our choice is between doing an uncomfortable thing now or having greater discomfort thrust upon us later. Because we procrastinators suck at choosing the lesser discomfort now, we effectively are choosing greater discomfort at times that are out of our control.
Making that choice is a skill. It has to be practiced to be developed. You can’t just start doing it easily today just like you can’t just start doing anything that requires skill.