What makes Calculus complicated is not understanding the basic fundamentals of Algebra and Geometry. The idea of Calculus is simple enough but it requires often understanding and solving rigorous Algebraic and Geometric problems. I took Calculus years ago and decided in Calculus 2 that I couldn't go on because I really didn't understand it, even though I got a B+ in the course. I decided to not pursue anything to do with Mathematics, even though I did like it. But as I reviewed Calculus over the years, I wondered how I even got as far as Calculus 2 after discovering my lack of understanding of the most basic Algebraic and Geometric principles. I guess I was able to follow the dots but I never was able to connect them. It doesn't do any good if you don't understand what you are doing because you will not be able to apply it.
My advice is to understand Algebra. Mathematics is about building relationships. Some people just can't get beyond 1 dimensional thinking. You have to begin to look at simple relationships like the reason there is Pi is because the circumference is 3.14... longer relative to its diameter. It compares their relative lengths. As simple as this is, people have a difficult time understanding this simple relationship because they are unable to compare things and are fixated on a 1 dimensional level. Most people function at this 1 dimensional level very well. They say they they don't need Algebra but yet the doors to the Sciences, Technology, Engineering and Mathematics are completely closed to you.
I always wished that Art was taught in conjunction with Mathematics in the Elementary schools. Art can nurture your mind to be able to imagine form better, as well as to improve imagination to allow yourself to be creative in your thinking by seeing Art also an exploration in relationship to go beyond that 1 dimensional thinking but that is another story.