I've been through this experience myself, so I know what you mean! The best resource I found was something provided by my local university called "Mathercize" (

I've been through this experience myself, so I know what you mean! The best resource I found was something provided by my local university called "Mathercize" (may just be something specific to them), which gave you a range of problems you could complete online, with a brief run-down of the theory on how to solve them. It was positioned as a "refresher" on maths for those doing college-level study, and in my case the problem sets were designed for MBA students. Maybe looking around for these kinds of refreshers rather than discrete textbooks in their own right is your best bet? I know that I encountered analysis paralysis when trying to re-learn "everything" from the ground up, and got nowhere as the information wasn't curated enough for my needs. Barring this, I found the "MathIsFun" to be the best all-round resource for grokking foreign math concepts.