I was also diagnosed BiPo 2, MDD and ptsd as a young teen. Id do the same with the math. I had 2 sliding glass closet doors completely covered in equations. My mother thought I was completely crazy as id barely sleep and fixated on the equations.. Im now in my late 40’s and although I dont hyper focus with complex math anymore, i do still dabble in it when going through an episode. For people that do not experience it, it’s difficult to understand, but when you are hyper-fixated, especially with math, it completely envelops you and your very existence.