Years ago at the Univ. of Ill. aeronautical engineering had the most math of all the engineering departments. We probably had the most statics and dynamics (physics), too. For Advanced Calculus I had a Prof that was in a bad mood. I was really depressed, but I ended up getting a B in the course and so I felt a lot better, but he had me scared for awhile. It really helps if you know Euler's Identity for complex variables. If your course is solely complex variables, you will need to know how to take integrals around a singularity thereby finding residues. Differential Equations is actually more than just simply integrating. You need to integrating factors, series, and lots of other things. In all these math courses it pays to not only have good math teachers, but also good books. In all honesty it doesn't hurt to have an easy grading teaching now and then, because that allows you some breathing room to keep up with the other courses during the semester. If you have a good book and the teacher is easy, you can always fall back on a good book, but you need to discipline yourself. It probably pays to do problems from the book. This is the hard part with an easy teacher, who does not assign much homework.
Overall, you probably need some love of math to excel, especially if you going to be an analyst. Program managers and project engineers do need to know the higher math forwards and backwards. There were a few times in working on the BS when I felt like quitting, especially with an unfriendly Prof. Once I got over those times, things went pretty well. If your passion is in this area, then I would say stick with it. Things will eventually work out.