Because no one else has done it, we often doubt that we can. That kind of negative thinking has several labels but the bottom line is that you must believe in yourself if you are going to accomplish your goals. Believing in yourself is very important. You may need to succeed at something to start to believing in yourself again. You need to reprogram your thoughts and feelings about yourself.
Nothing does that like success.
Once you begin to complete your goal steps, you will notice you are feeling better about yourself. Take a moment to enjoy that feeling. Tell yourself you are proud of you. Share your success with someone you trust and respect and let them tell you they are proud of you too. Make a chart and give yourself a gold star, if that is what you need.