Believing Makes it Happen
I have dear, dear friend who going through a period of self doubt. This is totally normal. The hard part is figuring out how to get out of the negative state of mind. It is totally addictive. It’s so easy to fall into that dark whole of self doubt and see only the faults. It takes so much more energy to be negative. I had someone ask me once, “How can I be so tired? I did not do much today and I am beyond exhaustion.” Then, she proceeded to go through a monologue on everything she doesn’t like about herself. It was exhausting just listening to her. You have to throw out the negativity. Don’t worry, the thoughts will never go away. If you really are afraid to lose any of your negative thinking, seriously, don’t worry, the thoughts will always be there ready to make you depressed. With that in mind, toss those negative thoughts and focus on your gratitude. 
Ask yourself, what do you want in your future? Find pictures that help you visualize what you want. Then, map out how you can get to what you want - figure out what possible baby steps you can take that can help you reach that goal. Naturally, you will find yourself believing and then it will happen. It’s impossible for it to not happen because you will be taking steps towards what you want… you see? Believing does make it happen.