When I was asked this a month or two back by my counsellor, after a brief pause my answer was 'me'.
I alone am holding myself back, so there should really be no problem.
Of course there is the fear but as we are 'transitioning' into a new life and reality, then we have to accept that there are unknowns, just as there were for our first puberty, but as most of us have some, or a lot, of experience in worldly matters, then these should really be seen as challenges and not blockers.
Everyone on this site will have experienced fear about some aspect of their life or journey yet we are still here. It shows that we are tacking life and its constant fluxes and changes of path. But that is what is so good about living, in that we can make choices to make ourselves and others happier and more content.
Sorry for the waffle, but when I start getting doubt or fear over doing something, I think of this, and not externalised fear factors and it work for me, I am in control so its OK.
I will get where I want to be, one day soon.
Hugz
Katie