My take on this (and this is not as a medical professional but as a former teacher) is that providing you can do the things asked of any private pilot, I.E pass your exams and pass your flight test then having dyscalculia itself shouldn't be a disquaifying diagnosis in the same way that having chronic heart disease would.
You may find learning to fly challenging, but as I'm sure you are aware people with learning diasbilities often have an amazing capacity to compensate for their learnign disability.
Having said that I have a Physics/Math degree and struggle sometimes. It's not easy for any of us! You won't know til you try.