How to tell my mom I'm worried about bipolar?

I know many people jump to conclusions on this, but I've done a lot of research myself, and I've gone through depressive, hypomanic, and manic episodes. I think it's probably bipolar 1, because I've only had one depressive episode and many hypomanic. My dad is bipolar, and it runs through the family. My parents are separated and my dad is off the grid, and my mom has so many things to worry about by herself. I want to tell someone, but she and I aren't that close, and I'm afraid that she'll think I'm overreacting since I just turned 13. I've no idea how to approach this, and I know every situation is different, but I could use pointers. Thanks a lot!