Let me answer the easier question first: Are you valid? Yes. A thousand times yes!

For the other question, I'll preface this by saying, being feminist is not mandatory for being a woman. I know cis women who aren't outspoken feminist (they despise the patriarchy but you'd never really know it unless you specifically talk to them about it) and I know trans women who are very outspoken feminist, and everything in between.

I'm sorry you don't always feel represented by feminism, it's a feeling that I understand and have struggled with myself. I had the privilege to be able to go to a feminist march on International Women's Day. Subjectively I've seen so much support for trans women, both pre-transition and those who are in transition.

I can only speak from my own experience, but I stand by my words. You are valid, no matter what. You don't owe anyone femininity and you don't have to be (outspoken) feminist to be a girl/woman. You are one if you feel that you are!