I haven't made it my business to tell the world. I don't think that's wise, personally, as I'm very much aware of the risks of the company one keeps - or has to keep even if you don't want it, sometimes. Stealth is something I decided on from the beginning. Only select people are aware, and almost all of them are far away. That's not to suggest cutting all ties for safety but to be careful if you are worried about violence or have problem people in your life. Some people want to tell everyone they interact with and make it kind of a statement about themselves - that's just not something I see a need for. I also did not "socially transition" first. I don't demand people see me a particular way before I looked the part. I do spend a lot of time to myself, so I guess I'm not constantly dealing with others making me feel crap, but neither did I want to exacerbate the potential negatives by being forceful. As it turned out, everyone came around organically in the end anyway, given a couple of years, without me even asking them to.
I can't speak for others, in my case the fears are greatest at the beginning. HRT then took almost all of them away, since it altered my mind state and removed most of my anxiety and preoccupations. I'm restless by nature, but with the wrong hormones in the system, or a deficit of hormones in the system, it's amplified. With the right ones, the state of nervous tension is lessened considerably. Time plays its part, too.
I wasn't so much fearful of others' reactions - I am self-sufficient in many ways and not worried about someone kicking me to the curb, or of someone getting a pronoun wrong, or anything like that, or even of someone wanting to attack, which would be a slim possibility where I am plus being expectant/prepared for that sort of thing anyway by nature. My fears were more of the medical sort, would I be able to get the medications where I was reasonably priced, would I react to them badly, would I be able to get the surgeries, would the T work properly, and so on. I needn't have worried.
Actually did not have high expectations of T or some vision of myself afterwards. A part of me felt it would not "work" very well. Maybe that's why I'm more pleased with the results than some end up being. There is still a way to go for it to complete its job, but I have not felt so relaxed and content in life with myself as I do now. Of course, that probably won't last and give you permanent peace - there are things I could not do with my life beforehand that I now want to do with a vengeance and end up champing at the bit for it. So the peace is shortlived and gets replaced by some other needs or desires, maybe. But it's obviously better than feeling inhibited by one's body, wasting valuable time.
I have no regrets with it. The choice was very clear and I'd explored all the avenues of my former life to the extent I was tired and knew it would not end in happiness by now. What tends to terrify me isn't what I do or what others do, it's the idea of regret. I would rather make a thousand mistakes than live a wasted life. That is my greatest fear, transition and uncertainty is a small thing in comparison, really, to the life I felt I was watching pass me by. And if this does not work out in some way, well that's fine - it was a necessary path. I thought about the worst case scenarios, and to be honest they did not frighten me. It is hard to be frightened when you are already numb to yourself and your predicament; when you already loathe your situation and history, or when you feel like you have nothing to lose. I do not have anything much to lose, so nothing feels like a step down.
But fear is normal. You'd have to have real problems not to have some of it when it comes to this subject. There are risks - family, spouse/partner/relationship, job, home sometimes are lost. But if you've taken the first step and decided you must do something, then you already know this and I assume know it's important enough to you to risk for. I would say once you start down the road, especially after T, your fears will seem more manageable.