The 'truth' can have a positive impact on family life - showing respect, getting along, standards for morality, honesty, working together, showing empathy, etc. But these qualities aren't the property of the WT publications. Many religions, communities...and families teach these same positive codes of conduct.
Having children grow up in this belief system makes the exit ten times more difficult. You have been very active and involved. I too once was - and raised kids in 'the truth.' It is the family's entire social circle. It takes time to reconstruct trust and faith. Leaving has repercussions. You can't avoid it. Like a divorce, when a family member exits it can turn everyone's world upside down.
Take your time. Talk a lot. Be honest. Express your feelings.