I think I felt something similar to this! (though I’m still trying to figure out where I fall on the aro spectrum). For me it felt like the pressure of heteronormativity just went full blast for the 3 months I was in the relationship. I had short, dyed hair that I loved, but felt like I needed to grow it out and have long hair. I liked presenting masculine, but felt like I had to give the more feminine version of myself. Or sometimes he would say something romantic and I would just feel no particular way about it. I felt almost suffocated in a way? But it had nothing to do with him.
It’s not until I’m reflecting on all of this after 2.5 years of not wanting a romantic relationship, realizing how I see romantic relationships as very “optional” for the lack of a better word, and picturing a future with maybe a QPR… but not really a romantic one, am I realizing maybe I could be on the aro spectrum.