It IS overwhelming. And it's normal to have doubts, apprehension, second thoughts.
I remember staring into the abyss of starting T, dealing with my ex, coming out at work, dealing with my students, changing my gender at work, deciding whether to bind (I still didn't, at that point), preparing for top surgery (and not being sure about that), knowing that I would be androgynous for however long it took, changing my license, changing my SSA info, taking care of less important things like Selective Service and my passport (might as well throw in everything so I can freak out properly), and all sorts of other crap that got piled onto the transwagon.
Whew!
I didn't deal with it all any too gracefully, but I know how I would handle it now. Now I would make a list of all of the things I am worried about, and categorize them. Legal things, social things, personal things. Some would be fears and some would be tasks; I would separate them. Some would involve talking to other people and some wouldn't; I would decide when the people-oriented ones might take place and jot down ideas for how to deal with them. Some would be things I can just go and do, and others would require multiple steps. The big tasks I would break down into little pieces; there might be several steps, but I'd try to make each step manageable. Some tasks would need to take place relatively soon, and some would have to wait; I would plot them out, month by month, and see that lots of things are pretty far in the future and don't need to be dealt with yet.
This sort of thing works for me because I can separate out simple fears from actual tasks, see everything that needs to be done, spread things out over time, and break things into small steps. And cross off each task when it's dealt with.
It can be done. You have to determined, and it sometimes helps to be very systematic. It also helps if you have support--even if it's just online support.