Considering the circumstances, now is probably as good a time as any to bury the hatchet and dive into khanacademy or whatever. Personally that is probably what I will do as this has felt like a big hole in my competency for a while now.
You should do that thing! I am working through third grade math on there right now because I have forgotten how to do pretty much all the math, and I also don't think I learned how to do any of it very well the first time. Join me!