If you da, you are making it clear that you are leaving willingly. It sounds like you are still living with your folks. Hm, that makes for not very happy living. Coming clean to her will likely result in living conditions that are not much happier. Living a lie is stressful though.
Here's a thought:
Victor Frankl, Holocaust survivor (he's deceased now). While I realize that I might be walking a line here, I just want to point out that no one can take away your freedom of thought, freedom to believe what you want to believe.
Here is a quote I got from this link: http://www.rjgeib.com/thoughts/frankl/frankl.html
Even in the degradation and abject misery of a concentration camp, Frankl was able to exercise the most important freedom of all - the freedom to determine one's own attitude and spiritual well-being. No sadistic Nazi SS guard was able to take that away from him or control the inner-life of Frankl's soul. One of the ways he found the strength to fight to stay alive and not lose hope was to think of his wife. Frankl clearly saw that it was those who had nothing to live for who died quickest in the concentration camp.
I am thinking about how you are living with your family still and that living with people, a mother, who believes with all her heart you are going to die at the Big A which, btw is imminent , can be a tad stressful. Right now, she has hope, once you do this, that hope is pretty much gone. It would be cool if you could find a way to deal with the stress of the situation til you're out of the house, perhaps meditation or yoga.
You sound pretty positive about the da thing sooo, to da or not to da that is the question:
If they df you because you come clean with your mom, you don't really know how people can spin it. Ya know make it sound like you are a harlot . Da'ing gives you the oppurtunity to express Why You are Leaving of your own free will and why you are not returning. If you intend on just coming clean to your mom, she'll know anyway and it's not like it'll be a big secret.
That means let it come from your heart. Why are you leaving? What bothers you the most? What contradictions or inconsistencies eat at you the most? Those are the things you include in your da letter.
Is it playing their game? Sure, but it also provides you a way to beat them at their own game by enlightening others who have doubts but could use the encouragement that they aren't the only ones who want out.
Good luck with everything!
