Female means "of or denoting the sex that can bear offspring or produce eggs, distinguished biologically by the production of gametes (ova) which can be fertilized by male gametes." And a woman is "an adult human female.*"
That's it. It isn't about feelings, or how you look or what your hobbies are, it's a biological thing. Unfortunately, in our world women and girls are often treated a certain way. There are certain expectations placed on us and it can be hard if you don't feel you meet these. But you're not alone, far from it. Don't be fooled into thinking most women 'feel' like a woman. They don't. There is no internal essence of woman. We are all human beings, individuals, with our own thoughts and feelings.
And it is completely normal to feel uneasy with your female form. Look at all the products aimed at making women "look better". "Hide your flaws", "Flaunt your curves", " Don't age" "Don't be vain" We are pretty much programmed into thinking our natural bodily functions - like periods - are disgusting. We're made to feel our natural faces aren't good enough. That make up is essential. It's a wonder we can make it out of the house!
But trust me, the female body can be so strong. So capable. We are designed to carry a baby. That isn't easy, trust me. But our bodies can do that and give birth and breastfeed. That's like a super power itself. Not saying evey woman should have a baby, far from it. But don't forgot what your body is capable of, that it is strong. Just have a look at some female athletes for more examples of how strong women can be. Rhonda Rhousey, Serena Williams and Jessica Ennis-Hill are some examples off the top of my head.
Best of luck.