My period feels like it never ends

Sky

My period is heavy, long, and irregular. I can't keep an exact count how long it is because in the middle of it it gets spotty then picks up within 2 days. After about a week and a half to almost 2 weeks the heavy stops and goes to spotty... too light for a tampon (I only have the super ones) and too heavy for a pantie liner. In the middle of the spotty it will go to discharge for a day, still too much for a pantie liner.

I have talked to my mom about a Diva cup for heavier days or at school. She said no. I briefly mentioned some form of thing to regulate them. My mom said "no, you don't need birth control at the age of 13."

Any tips?