I also worried about my ability in math and science with nursing. Math has always been my worse subject. I've always done well in science until it got into the math stuff. I'm borderline "discalculia" (a form of dyslexia in math) I'm a prenursing student right now, and decided to "test the waters" by taking a chemistry course. I figured that a college level chemistry course would determine if I could handle it or not. And I'm actually doing very well- pulling a straight A. But I'm also working very very hard to do this. I study every night, do all the problems in the chapter, plus extra problems from a chemistry help book that I have. It might be a little overkill, but so far it has been working.
Over the summer I reviewed the very basics, since I was freaked out about the course. I hadn't taken a real math or science course since high school almost 10 years ago, and I never did very well. (I don't count the math and science I took in art college as a real courses, lol) First I used a Basic Math and Pre-Algebra review book (there are quite a few good ones. I used the one from Cliffs. Love them!) That was a huge help. I couldn't believe how much I had forgotten. Then I used a Chemistry review book, doing the first few chapters so I would have a jump start on understanding the math in chemistry. Another big help.
It's taken lots of review and work, but I'll be able to handle it. For me, the key was all of the reviewing I did over the summer. Also, doing lots of practice problems help keep me from falling behind.If I can do it, so can you.
I think some community colleges have math courses specifically geared towards nursing students. A few in my area do, and I'm tempted to take one.