I have ADD and dyscalculia as well! Fear of math kept me from pursuing a higher education for many years. Honestly, I never found ADD medication effective, and I just sort of figured out ways to adapt. I sit in the back of the room so I can fidget/rock, and just invent little games to keep my mind from wandering. Sometimes I pick out a rhythm to bounce my feet to or use a piece of scratch paper to write out poems/song lyrics or draw while I listen to lecture, and sometimes I just take an unnecessary, ridiculous amount of notes to keep myself occupied. The first couple months were hard, but now that I've adjusted, it turns out the frenetic, hundred mile per hour pace of my mind is well suited to nursing school
! Sometimes I daydream or drift off in my own little world, but often all it takes is a five-minute mind-vacation to get you back on track.
As for math, the good thing is you only have dosage and calculations, no algebra, which is WONDERFUL if like me, you have problems with abstract mathematical reasoning or spatial reasoning. The first thing I did was LEARN THE FORMULAS. There are many different formulas you need to know, so what I did was memorize those, then when I got my test, the first thing I did was write them down at the top of my scratch paper. Test prep was the biggest part, though. I went online and did the same kinds of problems over and over again. In addition to the website we used that came with our textbook, I actually went on sites designed for kids and reinforced math that way too. LOTS OF REPETITION IS KEY! It was very comforting having a classmate with dyslexia, because I had someone to relate to when it came to struggling to understand what seemed to be a cakewalk for others!
You must understand: Much of the time, math anxiety is a worse problem than the learning difficulty itself. You are not broken, and you are not disabled; your brain simply works differently, and it just takes a little more effort to find the correct answer. You do NOT always have to understand why an answer is correct, just know and trust the formulas!
It's okay to be frustrated, too. I have an IQ of 147 and an exceptional working memory (when it comes to language only, lol, go figure numbers and abstract values are excluded), so I used to get really, REALLY upset when most things came effortlessly, yet this one damn thing was an absolute battle! Just know that people with learning disabilities get through this stuff every day, and you can do it too!