Why can't I memorize anymore?

[I am not gay]

I have Memory problems that i study for hours and in last i get 0 result Seriously I Cant memorize or Concentrate things I read? Whenever I study anything, I learn it at that time but I forget it in the near future.. I'm not able to remember things I study.. What can I do? Please help I already failed in Math/Physics Last Year + I tried to find solution in Youtube their shits aint helping me , its ruining it >My Brain>
- Bad Focus
- Low Memorize
- Hard to learn as an adult person / Takes Time to understand something or definition or math equation its just that I'm Slow at learning.