As the only JW in my family, I know I distanced myself from them. It hurt "knowing" that if they didn't join me in happy dubdum, they would soon be destroyed. I created a barrier because I hurt all the time. I was totally convinced that I had found the secrets of the universe and couldn't understand how they couldn't see it.
It became more and more difficult to carry on conversations with people outside of the org. Things my relatives and old friends thought of as important, (ie... their future, work, kids' sports activities, recreation, education, holidays...okay, almost everything), wasn't important to me, especially in the beginning while I was in the first flush of theocratic zeal.
My marriage was already in the crapper by the time I became a JW, so it didn't really have an impact...only allowed me to view our impending divorce with more equanimity...which, looking back, was probably a positive thing for me.
I feel so bad for those of you on the opposite end of this who are having or have had their family lives destroyed by someone you love being trapped in the sticky web of the WTS.