I feel like my sister doesn't support me

Explaining Bigender and Polysexual

Hi! Firstly I changed my name to YourLocalPolysexual due to my realising that i'm polysexual with a preference for woman and a DemiGirl. After realising this I kept it a secret from my family until today (or the time I'm writing this) I was searching up random thing on the computer when my sister asked me to get some water, I said no and to get it herself and she said "If you get it your gay- I mean straight" which is a normal thing for her to say since I told her I was a lesbian. But then I told her you do know I'm not gay anymore right? That was the beginning of this argument then I told her that I was poly. At first she was confused then I had to explain it in more detail. That I liked all genders excluding men and demi boys she had to look it up after and she got it but what she didn't understand was the it meant by all genders. I told her how there is 42+ genders and she looked dumb founded. She asked me to name some and I started with Non-Binary she understood that then I went to bigender how it's when you don't know what your gender is so you change it often (A great example of this is Osana Najimi from Komi Can't Communicate who's gender, as the manga shows, is Najimi) she thought it was stupid. Like it was a dumb gender and we didn't need it. I was flabbergasted she kept on saying that the LGBTQ+ community is stupid for making up these genders and sexuality that don't matter she said that to just say that your Non-Binary or Questioning and to just not creat a whole new gender for it.

Comment your opinion on her reactions to see if you can give advice.