Keep moving towards your goal. You'll make mistakes but don't quit. You may even have to hang on after others have let go. Persistence means taking pains to overcome every obstacle, to do all that's necessary to reach your goal. In the end, the only people who fail are those that do not try.
All great achievement takes time.
You don't need an explanation for everything. Recognize that there are such things as miracles, events for which there are no explanations. Later, knowledge may explain those events quite easily. The fact that you can plant a seed and it becomes a flower, share a bit of knowledge and it becomes another's, smile at someone and receive a smile in return are common miracles. Your duty to yourself is to believe that for which you have sufficient evidence, and to suspend your judgement when you have not.