You don't need a publisher, 100% will come to you. A good publisher might get you more placings for your song but you have to give up 50% of income and 100% control of your song, unless you find a publisher that will take a smaller percentage. Watch out for bottom feeders, they are out there a dime a dozen. I've been burned before so make sure any publisher is legit and able to actually help you before you sign. Good luck.