Forget the maths (unless that will actually help you) focus on ONE subject a time and don't jump ahead to the next three subjects on your mind because you are running them in together and mixing them up. Take ONE subject at a time, like before you wrote that I would have expected you to actually study gravity first and then after understanding that studying electromagnetism, not just make up a bunch of stuff throwing in a few out of place scientific terms here and there and getting them all mixed up.

One thing at a time. Learn how gravity works. THEN learn how electromagnetism works which is a totally different thing and keep the ideas separate, each subject could be 100 essays in their own right, they are not really related though only in the sense that they both exist in the universe which would be a pretty broad span of things to try and tie to together.