don't be so sad, bisexuals makes up a big precent in the LGBTQIA+ ... just because someone (who isn't bi them selfs) said it doesn't exists doesn't mean there right. I can confirm it, im bi my self and my friend is too and there so much proof that it exists, like.. do you think Megan Fox is confused or that girl from 5h or Billie Joe Armstrong are too?
Tbh if your future bf or gf is not supportive of you being Bi... JUST DUMP THEM. you dont deserve that kind of a headache lol