Oh dear.. where to start? Coming out to anyone significant is a scary process, because it can put the relationship, any relationship, to the test. I think the scary part is not knowing for sure how someone is going to react.
I feel that some things need to be taken into account before you come out to anyone important, especially parents.
The first is that the truth is usually uncomfortable, and at times painful. Nobody enjoys being told the truth, even if they say they do. So one of the first things I would think about is how you are going to tell them, the delivery of the truth.
The problem here is that most people don't have an issue with someone being trans .. as long as it's someone they don't share a relationship with. Nobody gets upset reading about someone who is trans in a magazine or newspaper article, but some do when it involves someone they know or have a close personal relationship with.
It's basically because you're bringing that what you've been keeping inside out in the open. Being trans to most people is usually way off their radar. Sure they hear about it, read about it, but they generally never anticipate someone being trans who they know personally. This means that usually when it happens it comes as a great shock.
It comes as a shock because they've had dealings with you, they know you, or assume that they know everything about you, and then all of a sudden they're placed in a situation where they feel they know nothing about you. Often in such a situation the mind goes into overdrive and all sorts of fears and assumptions come to the surface. Are you gay? Is this some sort of temporary thing? What have you been doing on the Internet? And so on..
But it's important to keep in mind a few things. This is about you, it's not about them. It affects you, your identity, your ability to express yourself, your basic ability to function in life (which I feel personally is the most important), your ability to feel and perceive such things as love, happiness.
It's also important to make them aware that this isn't something that's come overnight, or as a result of reading something on the Internet. It's been something that you've been dealing with for a long time, something that you've felt scared about sharing with other people because you fear their rejection and more importantly it's something which has not only challenged the way you see yourself, but destroyed it. You accept that it's come as a shock to them, and you understand if they need time to come to terms with it.
More than this it's important I feel to tell them that it's just your gender identity which is changing, and that you're still the same person as you were before, it's just that you're going to be much happier and find it easier to deal with life than you were in your former identity.
I'm also in the camp of telling them before starting any major treatment. Going behind someone's back is never a good strategy (please remember coming out is all about being honest and up front with people) especially with parents because you risk damaging their trust in you. I feel it's always better to bite the bullet because it's going to be much better doing things openly with their support. That to me is always worth the risk of telling them, and I'd much rather take that risk than risk alienating them by going behind their backs.
Whatever happens I hope it goes well for you, whatever you decide.
