I like maths but I'm a CompSci first. Going to full-math mode is not easy after years without practicing. For example, the first 6 months, I spent a lot of time bringing back memories of basic stuff. In my case : probability calculus (the very basic stuff, expecations, conditional probabilities, etc.), Bayes theorem, least square derivations, Lagrangian, linear algebra, simplex method. Be sure to reach a teacher at some point because these "simple" things are actually quite fundamental and thus sometimes hard to grab.

After that I can understand more complex stuff: GAN's, GLM's, SVM's, PCA, you name it... Things that were totally alien to me 1.5 years ago.

But well, just do it, in any case you'll be better! And proud of yourself!