Math encompasses quite a lot of territory, so I think it's important to identify the parts that have most relevance to your specific areas of professional work.

Math encompasses quite a lot of territory, so I think it's important to identify the parts that have most relevance to your specific areas of professional work. Learning math can be very difficult and frustrating. It's very easy to be overly hard on oneself ("I suck at math", "I'll never learn this", "I must be stupid", etc.). As others have pointed out, it's something you have to grind away at it. I think the takeaway is that for most people it's not something you instantly pick up. There are multiple ways of explaining the same concepts. If the book you're reading isn't connecting the dots for you, it might be helpful to read about the same topic in another book or two. A different author may provide one or two sentences that make the concept click for you. If you're taking an in-person class, the instructor might make the class really pleasant and insightful or really nasty and painful (or anywhere in between). I remember entering a Calculus II class in college and the instructor was an ass. He was nasty, bitter, smart-ass, etc. always. I believe he was hating his life and his attitude brought some misery to those around him. I dropped the class. It was toxic for my ability to learn the material. I think it's always best to quickly reject toxic instructors and find one that's not toxic. Lastly, get a tutor. I've done this when trying to learn (or re-learn) some math when I was in graduate school. It made a huge difference.