Get the AOPS Pre-algebra, Algebra, Geometry, Pre-Calc, and Calc books. Do every single problem in all of them. Do every single problem in Stewart's early transcendetals, you can get the latest edition (9th) on libgen, supplement with professor leonard's lectures on youtube or patrickjmt. Then go through a discrete math textbook + Hammack. After that either Calculus by Spivak or Calculus Vol. 1 (my favorite) by Apostol.
Discrete math:
http://discrete.openmathbooks.org/dmoi3.htmlBook of Proof:
https://www.people.vcu.edu/~rhammack/BookOfProof/Supplement precalc with:
https://faculty.utrgv.edu/eleftherios.gkioulekas/OGS/Santos/santos-precalculus.pdf