I am a retired hypnotherapist, and I have worked with many patients with a variety of concerns. The benefit of hypnosis in your situation is not to convince yourself of something, but to help you relax and be less anxious about it.
From what you have shared, I do not believe it is what you are looking for. The key is to find the things that make you feel good and embrace those. It can be as simple as jewelry, or clothing, a hairstyle, or even an old, beat-up pair of boots. Once you find the look you are going for, then you can work on other goals.
You have mentioned that you are often seen as male, so your clothing and mannerisms work in that direction. You also said you were going for something androgynous. I assume you mean less Macho Man and maybe something a little softer? As Marion mentioned, you can do that by the colors you wear, like more pastels and less Army camouflage. I am giving you extremes, and they may not be what you are looking for. But maybe they can help you look in a direction you hadn't considered.