I've been self-learning math and physics topics for the fun of it, and I'm not quite sure where to go from here. So far, I have a firm foundation in differential, integral, multivariable, and vector calculus. I'm working on differential equations. I don't know much linear algebra at all. My purpose in learning math is so that I can understand physics topics. So far I've covered pretty much all of classical mechanics, including thermodynamics, and I have a firm understanding of special relativity. I'm currently working on electromagnetism. My goal after E&M is to move onto general relativity and quantum mechanics. This in mind, by question is: mathematically, what should I work on next? I know I'm going to need to learn things like tensors, differential geometry, topology, and stuff like that for general relativity, I just don't know what specific order would be best to learn the topics in. So what order would it be best to learn those in? Thanks for the help!