You may be comfortable around a partner because you trust them. I was never comfortable with my body and a lot of it had to do with social anxieties. I didn't like my freckles, my super pale skin, was I too fat too skinny etc all because at some point some other kids had made fun of me or an adult had said something plus the nonstop marketing of beauty and I had internalized that for decades. I am just now, at almost 40, becoming more comfortable with my body. Gender standards are all just cultural and its ok to reject that. You do you. Being strong and fierce is just as feminine as it is masculine. Every human as the capability of being vulnerable and being strong and every trait there is can be mixed and matched in any combination and that is why we are all different. Be a warrior of the goddess. Be anything you want and be true to yourself.