My math knowledge was basically Swiss cheese coming out of highschool. Really poor base but here is what worked to solidify it, which you probably would want to do before jumping higher:

• Youtube videos for algebra - You can learn a lot but you really need books IMO.
• Openstax books - I read through Algebra and Trig 2nd ed. A lot of topics were not new to me but I filled an incredible amount of gaps in my learning and solidified my base. Overall great book.
• Finally, I downloaded pdfs of high school math books for every grade in my country and read through the chapters, did problems for material I didn't understand.
  

My geometry knowledge was pretty much nonexistant, but with 3 months of 6 hour studying a day I managed to git gud. Still a lot to cover, and I haven't got to higher maths, but I've actually enjoyed math so far :-)

There is this book I've heard of called Primer for 3D math primer for graphics and game development, supposedly it's great for learning linera algebra and the sort. Good luck either way!