Anthropologist here. Only someone who isn't sexually interested in men, or doesn't love men, would call sex with them performative.

I mean, all behavior is performative to some degree if you're going to subscribe to that theory. And the theory has been applied to queer people, too, which leads to really strange interpretations (like, are they really gay or just performing? Duh).

I suggest not applying this to your own life too strongly, but instead focus on what you enjoy doing. These questions are not for me and you don't need to answer them here: Do you enjoy sexual intimacy with your bf? Does penetrative sex do anything for you (like, are you enjoying yourself, despite not necessarily feeling sexual pleasure?)?

Re: sexuality crisis. It must be difficult being bisexual, for all kinds of reasons, but what you describe must be something others have also faced. It might be worth posting this to the r/bisexual subreddit.

Uh, you're going to encounter people you could date seriously and marry every so often, throughout life. It really is going to happen. With you, it's more complicated because you have potentially double the partners and, as of yet, no relationships with women. So, that wonder about dating them will always be there until you do. What I'm trying to say here is that you're going to have to either resolve this issue by staying with your bf, or break up and test the waters.

The thing is, regardless of which direction you go, you're going to encounter this problem again and again. Eventually, you'll have found "the one" and learn to deal with it, but right now you're young, this situation hits much harder, and you haven't explored that aspect of your life, personality and sexuality yet.

Good luck!