I had a strong sense of my female self since before my teenage years
Did you mean to say 'a feminine side' to yourself? As a male, how could you have a 'female self'?
And yes, in our society there are some differences between how men and women present that are an expression of sex/gender.
But why do you need to declare that you are some sort of 'woman' in order to present in a way typical of women? Why not try to break down the gendered expectations of presentation? This is what women did through the 20th century. At the start of the century it was unacceptable for a woman to wear trousers. By the end of the century it was completely normal.
Women can dress from head to toe in clothes designed for men, have short hair and wear no make up, and people don't even notice - or if they do, they don't comment (I know, I've done it). By continuing with the argument that there are certain presentations which are only for women you perpetuate the idea that women should look a certain way. If I don't present in this way that you say is an expression of sex/gender appropriate for women, does that make me less of a woman? How does it benefit anyone to perpetuate harmful gender stereotypes?
You seem to be making the same argument as the children described by Katie Alcock (quoted by R0wantrees):
James is firm that having short hair makes him a boy, and that it also makes other people (and dolls) into boys. My own child aged four was convinced a teenager we knew must be a boy because she had short hair.
Until the age of about 7 (yes, 7 — in some children it’s older) children think that when something changes its appearance, its underlying reality changes too.
Just because there are 'rules' about what is acceptable and unacceptable attire for one of the sexes, it doesn't mean that your sex somehow changes if you break those rules. Yes, women do it more than men, but that is relatively recent - it's only in the last century or so that women have done this in great numbers. But why can't men start breaking the 'rules' too?
Nothing in your post has convinced me that your belief that you have some sort of 'female self' isn't entirely based on sexist 'gender roles'.