Explaining with NO Apologies
First things first. If you have a son or daughter who has come to you and told you they are transgender, it's going to be okay! It may come as a shock to you, or maybe you suspected something was going on and the news confirmed it. Again, you are not alone and this is not the worst thing that ever happened! This is simply a fact of life that this person has finally been strong and brave enough to share with YOU.
Learn As You Go
When you become a "new" parent - of a son instead of a daughter or vice versa - there is a big learning curve. Acceptance actually comes easier than the day-to-day "stuff" like using the new pronoun, remembering the new name, and helping each other through the transition phases ahead. Remember, your child has had a lot of time (probably) to deal with all of this - they may have been using the new name with friends who have known well before you did. It's going to take time for you to get it right.
Talk to your young adult/adult child about understanding the learning curve. Make a deal with them so they don't get mad at you when you call them the former name, or say "she" instead of "he" four times in a row. It's not that you don't "get it," it has to do with using these words for 18, 19, 20, or more years! It takes time to change even these little things.
Realize the History
Emotionally, someone who is transgender has typically had many years (or a lifetime) of confusion, frustration, angst, and internal explosions of being royally "screwed" by life. They may have spent countless years in silence - trying to hide the fact that they don't fit into their own bodies, let alone your plans for their life. IMAGINE their pain. Keep that in your mind when you are making decisions or having heart-to-heart conversations.
Keep Your Emotions In Check
It should go without saying, but let's say it anyway...Be careful what you say in the heat of the moment. You can't take back what has been heard, and your son or daughter has taken a huge, bold step toward you in sharing that they are transgender. Listen. Love them - tell them "We'll be here for you" and "We love you" so that they don't feel they will be rejected by the people who are supposed to love them NO MATTER WHAT. This is your only chance to put into action what you have told them their whole life long - "I love you no matter what!"
In Desperate Times...
If you have someone in your life who has tried to self-harm or commit suicide, you know the level of despair we are talking about - from a parent point-of-view, it is the worst of a helpless situation.
Nobody wants their kid to feel pain (well, nobody who isn't on a t.v. reality show anyway). It is devastating to imagine your beloved child feeling they could not come to you for anything. NOT HAVING PARENTAL SUPPORT is often a key factor in the difference between a supportive/successful transiton and one that has a very unhappy ending - a split from the family entirely, or worse.
You can make a difference.