Ting, I feel your pain. I was terrible at math in school. It made me feel like I was dumb, even when I knew I wasn't.
What eventually made math start to click for me and actually become something I enjoy was a book I read.
I've always been interested in physics and read a lot of books about physics and physicists. One of my favorite physicists is Richard Feynman, so I've read a lot of books about him specifically. One of those books was "Surely You're Joking, Mr. Feynman!".
In that book, and several others I read after, Feynman talks about how he struggled with the way math was taught and how that differed from the way he thought about math. To him, math was very physical, something you had to be able to see. He didn't do very well working through problems on paper ("showing his work"). He had to be able to see it in his head. He also talked about how mathematicians and physicists actually do math - they use shortcuts to estimate, which is good enough for most practical purposes. If you need precision, you can use a calculator.
I'd never thought about math this way before. I hadn't even considered that my problem with math wasn't that I wasn't "good" at it, it might be that I didn't understand it the way it was taught to me.
So I went online and started working through Khan Academy's math courses, which teach math more in the style that Feynman had talked about. Within just a few of the courses I started getting really excited. It made sense to me. I actually enjoyed what I was learning. I was even pretty good at a lot of it.
I don't know if this will work for you, but it might be something to try. Sometimes attacking a problem (like learning math) from a different angle will help you get past a roadblock.