Espenoah.
How about this.
Make a list of all those you want to tell.
Then, divide them up into, those you want to give the full monty, explainations, sympathy, references to your own background and growing up and stuff, a second of those that will just need the basics, that you're not growing horns and you still care about them. Then the third, those that just need to be told. If they want anymore information, here's a link, ect..
To the first group, just tell them what you told your mom.
The next two, remove those bits you don't think they need to know.