Thanks you are all really helpful i appreciate it. Differential equations wise I am only familiar with solving certain first orders using separation of variables, direct integration and integrating factor. I think I will start on techniques for certain second order differential equations.
That link is great too thanks again, you are right definitely enough to be keeping busy with.
My physics is very rusty (again A levels were quite a while a go), however I would like to take some physics modules. I am thinking perhaps classical mechanics and special relativity, electricity and magnetism and quantum phenomena. Does anyone have experience with these modules? Were they enjoyable, interesting, useful etc? Also how might someone fair who is quite rusty at physics (although willing to put the work in)?