1. Do I need to be good at math to become a hacker?
2.  
3. No. Hacking uses very little formal mathematics or arithmetic. In particular, you won't usually need trigonometry, calculus or analysis (there are exceptions to this in a handful of specific application areas like 3-D computer graphics). Knowing some formal logic and Boolean algebra is good. Some grounding in finite mathematics (including finite-set theory, combinatorics, and graph theory) can be helpful.
4.  
5. Much more importantly: you need to be able to think logically and follow chains of exact reasoning, the way mathematicians do. While the content of most mathematics won't help you, you will need the discipline and intelligence to handle mathematics. If you lack the intelligence, there is little hope for you as a hacker; if you lack the discipline, you'd better grow it.
6.  
7. I think a good way to find out if you have what it takes is to pick up a copy of Raymond Smullyan's book What Is The Name Of This Book?. Smullyan's playful logical conundrums are very much in the hacker spirit. Being able to solve them is a good sign; enjoying solving them is an even better one.