Out of the blue just started having a bunch of bisexual angst about the fact that I’m in the...

Out of the blue just started having a bunch of bisexual angst about the fact that I’m in the best relationship I’ve ever had and I’m terrified of really committing to it because I’ve never dated a non-dude and though I don’t feel like I’m missing anything being monogamous with him, I feel like my bi-ness will never be ‘real’ or valid until I date a girl/nb chum. And now I’m really mad.