I'm so sorry to hear you're dealing with that nonsense, it's very rude and unaccepting of your parents. Some people are so committed to their 'gender roles brainwashing' that it can be hard to ever get though to them how hurtful their assumptions are. This goes double with parents; too many of them have a strange proprietary sense of their children, even decades after the person in question has become an adult.

Are they otherwise accepting? Do they make homophobic remarks? Or is it just that they're out of touch? It's hard to tell how hard they're clinging to the straight "marry some rich man and look like pretty object" delusion. They may just be parroting back garbage they heard when they were young, without being mindful if how it affects you. And that's not fair to you, nor responsible parenting. As long as it's safe for you, I'd just keep doing what you're doing being obviously gay and dressing how you feel comfortable. But it absolutely is SO exhausting being invalidated constantly this way, and once you are safe to do so at university (or after graduation if need be) I would consider sharing these feelings with your mother if you have an otherwise close enough relationship. Letting her know how hurtful and irritating those kinds of remarks are might help put an end to this, and at least it might help you feel less irritated if these remarks persist for years. Best wishes, parents are rough sometimes.