Comprehension Problems, etc... dyslexia?

You very well could be dyslexic. The symptoms you describe fit the diagnoses. First of all, don't worry about what others do. How long it takes you to do something versus how long it takes them. It just doesn't matter. Concentrate on yourself. If you write things backwards, but notice it right away shows you are compensating for your mistakes. Reading out loud is a good way to make sense of what you read. Also, when doing something talk yourself through it - also aloud. It doesn't surprise me that you take a long time on quizzes, but there is nothing wrong with that. The race isn't to the swift, it is to those that get it right. It is also not unusual for dyslexics to have problems with math. It is very important to be as organized as you can be. Use colored folders - one color for each subject. Make sure you put everything away right away. Ever hear of the saying "A place for everything and everything in its place?" That is especially important for dyslexics! Decide on a place for important things and then always put them in that spot. Even to the point of putting tape on the table/desk/whatever in the shape of the item. It helps as a reminder of where it goes. It is so important that you always put things where they belong right away. Don't be afraid to ask questions. What you don't know may be what others need to know either. It probably isn't common knowledge. Ask what you need to ask. I don't think the motion-sickness and headaches are related to dyslexia, but I am not a doctor. And yes, I am dyslexic and have learned to compensate for my "disability" and so can you. I am also a recently retired special ed teacher.