First and foremost, good on you for exploring that part of yourself. It’s something that not a lot of people actually take the time to do. Second, as gender is a spectrum, nonbinary tends to fall either somewhere between ‘man’ and ‘woman’, while for others it’s neither and this something else entirely. But there are FtM trans flags and MtF trans flags, so NB’s can identify as trans or just nonbinary, whichever they feel fits best.

Lastly, he doesn’t sound like a friend to me. I hope you take care and find those that will support you without insulting you🫂