Ask HN: Astrophysics for a guy who can't remember highschool math?

Hi HN!

I've had this unfaltering fascination with astrophysics for years now. I studied CompSci in university and always kind of wished I'd taken more math courses.

I'm at the point now where its not financially responsible of me to go back to school to pursue my passion. So my question is; what online resources would you recommend for a techie who can barely remember his university math, let alone highschool?

More specifically, where can I start(from the beginning) to work towards learning more about astrophysics?

Thanks!