I have spent most of my time worrying about things that have never happened. Worrying is not an action! In fact, it is action that alleviates concern and dissipates worries. Take more actions when you feel that worry is creeping in to steal your time. It need not be a huge action, any action in the direction you want to go will do.
When I was fourteen, my father was so ignorant I could hardly stand to have him around. When I got to be twenty-one, I was astonished at how much he had learned in seven years. See what happens when you "know it all", at any stage of life? Farther down the track you may see clearly how certain personal opinions, held onto too tightly, could be fogging up the view, and providing incorrect insight. Prosperity is the best protector of principle.
All you need in this life is ignorance and confidence; then success is sure. You can "already know for sure" things that could actually impede progress. Always be on the lookout for the things you did not know, that you did not know. Secondly, work on strengthening personal belief that a particular will be achieved regardless of any adversity that may show up, or evidence to the contrary.