Yes, I too think tat the thought of never being able to be cis sucks : / But you are biological a woman. I cannot think many man that would like to be associated and perceived as a girl (so I would say your brain is mostly female?) and you are on MtF HRT, which makes your whole system female. And as I have tried to explain in my first comment: You don't have to dress in any stereotypical way! You are allowed to wear baggy jeans, or Shirts, or anything really~ same as guys are allowed to wear nail polish, dresses and other feminine things. Cloths wouldn't make you less of a (wo-)man. Personally? I sometimes love looking like a 14 years old pre puberty boi, other times I like dressing a bit more feminine and god I love my black nails :D

I think it is not really internalized transphobia you are experiencing; I think it's rather more either your personality, or maybe it's about you not letting go of your masculinity? Maybe you could try to start presenting more androgynous and than fade over to a more feminine style. But than again, don't sprint to something you would feel uncomfortable with, and if you feel more comfortable presenting more (or most) masculine; I guess rock your tomboy/butch style than? I would say if you identify as one, you are a valid woman.