I've always wanted to be a freelancer but I'm not sure whether I will be able to survive as one. What are some traits that are essential in order to be able to really take freelancing as a career?

Whether it's a freelancer, or a business, the most important skill is your ability to get someone to pay for your services/products, in other words, getting something sold aka sales. Most of the successful freelancers i've worked with at good at the sales part of the equation: they are able to reach out to good, qualified, willing buyers (e.g. marketing), convince the buyers of their value and price (sales). Of course, you still have to be reasonably good at what you do in order to deliver a good service/product.