Hi LIT. Another non-jw falling for a jw here! Tried everything and more to "wake him up" after he went cold on me. Found out he was a jw by googling his name and long time poster on this site blaming him for wrecking his life/marriage so should have read the warning signs. All he would say when asked him if he was a jw was not all are bad. Then the rot set in and few weeks later, literally overnight, nothing. I will never know what happened but can only guess he put the WT first and wanted out in case they found out he had been "bad". Tired everything to make him talk or open up but nothing. Hard pill to swallow but have to accept he had his fun and now he is back in the fold or moved onto someone else. Like you I did feel partly responsible and thought it was my fault but now know this is not true!!
Good luck for future and hope you find peace.