A CS major will have at the very minimum, one class on discrete math. Often an IT major will have one too.
For those subjects, you're expected to be capable of highschool level algebra, and that's about it. The rest is logic and notation. Definitely take a look at some of the first year subjects and their prerequisites/assumed knowledge.
I would certainly recommend brushing up on your maths before you go to college if you're going to study CS. Khan Academy is pretty good. If you learn everything up to pre-calculus you should be fine.
I would also suggest as encouragement that if you're compotent at programming you almost definitely have the capability of being at least compotent at maths. Highschool maths is boring and generally taught by uninspired people who can't explain anything to you because they're teaching from a textbook. University math is fantastic. Most of the time when you're taught a rule or property of some sort, the lecturer will prove it to you immediately after which makes it a lot easier to understand and remember (even if you only understood half of the proof).
Personally I thought I was bad at math until I got out of highschool.