NAD,
Don't despair. I'm not sure of your particular circumstances, but it sounds like you have family in "the truth" and you want to leave without alienating yourself from them.
If you are financially able - move out. Continue to go to meetings and slowly ease your way out. There will be a time when first your family, then the elders visit you and urge you to return to "the flock"At this point you will have to stand your ground - state what you believe and above all DONT ARGUE with them. In their eyes they can lose sheep, but not an argument - thay are always right. If this is done with tact you may be able to maintain good relations with your family.
Hopefully your family will understand - maybe even see it from your side, but you have to prepare for the fact that they may not.
The longer you've been in the harder it will be to leave.
I'm not saying this is the only way to do get out, just one way.
Hope this helps.