The existence of trans people doesn't enforce that concept but instead goes against it by suggesting these identities are changeable/mutable.
Do you, presumably a straight cis man understand that? What are you going to do to fight that reality? I don't understand cis people. They do realize that 'gender' is a product of the material conditions that help to reproduce capitalism right?
Shift your framework away from avoiding 'degeneracy' and preserving the order and realize the order is what got us in this mess in the first place. Leftism is not just about class struggle and workers rights but also about an erosion of hierarchies and destabilization of the status quo. One can not exist without the other. The systems of control (i.e. gender. race, borders, etc.) all work together to oppress the working class.
Also stop trying to belong/fit in somewhere. Just be lol.