A lot of trivial reasons are usually the causation of our procrastination. When we later think about them, it is really a regretful feeling, knowing that we should not let that opportunity to pass with seizing it.
An approach that I have read and also experienced myself which can help in this regard is asking yourself: Why are you not acting? Why are you procrastinating?
Try to not let yourself escape answering this Why and after you have answered, think whether that reason is a valid excuse of not acting. Procrastination and excuses are some of the biggest thieves of our accomplishments.