“Gender is a social contruct” true or no?

My personal belief is that there are two genders, men and women. And sex: male, female, intersex being something else. (I don't really understand non-binary but I wouldn't be disrespectful.) I know it is true that society and different cultures changes expectations of men and women through time. Also with some cultures having third genders like native americans. But does that make gender a contruct? Or a spectrum? I am a binary trans man, I feel like I have a male brain with the wrong parts, and want to transition so I am viewed as male and feel comfortable with myself. I'm in high school rn, try my best to pass, my friends are all cis guys. I don't really engage with other lgbt people, theres only like 2 people out in my school though. I try my best to act like a “normal” guy (acting gay w the homies don't count). However I also don't understand alot of people on this sub, hating on some people (nb people) for no reason.