I would be the first to admit that I am not the best at math, either. But I do understand the fundamentals that I can build off of and that eventually helped me earn my degree. I wouldnt focus too much on what your grades are, but instead focus on your development of concepts and learning. If you have all the basics down, the rest will come easier. What is most important is the passion, and it sounds like you really like chemistry.
Having great communication skills is really important for engineers, and a great asset to have. I suggest looking at the different jobs that the chemical engineer women have on this site to see what different career paths they have. Chemical engineers can do anything from pharmaceuticals to clean energy, fire protection and many more.
As far as the exams it would depend on your country, the University and what field you want to get into.