Hi,
I would talk to the professor who is going to be teaching the class about your anxiety. Often universities (sp?) have tutoring available through the department or other student services for core classes like the ones you are looking to take. They are usually free to the student and you just have to sign up for them. Sometimes you need a "referal" from you professor, but you should be able to get that. If you see the professor before hand he or she may be able to suggest some exercises you can work on this semester to get the math skills you have refreshed. (I'm assuming it has been a while since you took math.) Also take advantage of your professors office hours when you have questions that come up. That way you can get the one on one attention you need. One thing I heard a lot in undergrad and now in graduate school is that professors would always like it if their students came to office hours more often. I don't know if it will work with your schedule, but if it doesn't then set up another time to meet with your professor.
I hope this gives you some direction. Ask if you have any more questions. Good luck.