congrats man - don't let people doubt you. As an entrepreneur who left my full time job to start a business, taking the leap from safety to uncertainty can be scary but it pushes people made for it to greatness. most people never make the leap, which is why it's weird to them, but also why you will win.
about the $$ - everyone has a number financially that works for them to make them "full time" - i think it's easier if you're younger without a house, tons of bills, kids, etc (why didn't i start in college?!) haha