How do you not give up on dreams that seem outrageous

Its silly, one moment i have the confidence that could make me king of the world and the next i feel like i could never amount to anything close. Does anyone know how i could get over these weird doubts or is it something that really needs to be there so i dont give up. And is it really all that great if it makes me wanna give up sometimes

One thing I always did was to make sure that you have your passions be a strong hobby. At one point I was a professional wrestler about 8 years ago, no WWE just small local league. There were hours upon hours of lifting weights, increasing stamina, and practicing in my free time that wasn't spent working. Most importantly, don't be afraid to fail. Did I want to make it into the big leagues like the WWE? You bet I did, I didn't quite make it. At least I gave it a try and it made me a better person, and the same applies to everybody in everything.

Staying positive is a key. Those thoughts of self-doubt tend to take root and fester the more you let yourself get into a slump, so I tend to just get up right there and do something to make me feel better, be it going for a run, or watching anime/gaming. Getting support from your family/friends is also a really great idea. Don't feel bad about telling your dreams to them. They will remember them and give you a lot of encouragement.

Family can be like that. The important thing is to be happy with yourself and not care what others think of you. Do what you enjoy (as long as you are not hurting someone), get a hobby you are passionate about (like anime :P), set short term and long term goals for yourself. Be you.