First of all, welcome to JWN! Now, take a deep breath and exhale...you've come to the right place. There are many people who have stood where you now stand that will be able to advise you on your next steps as well as share their own personal experiences.
Let me start by saying what a shame it is that your father was treated with such contempt. I'm quite certain that doctors knew all about dementia and mental deterioration from a stroke back in the 70's. But the WT and its minions would rather just get rid of a naysayer regardless of his circumstances. As a frequent JWN poster says, "Cults shoot their wounded!".
Although your mother is physically out of the cult, she is still mentally in. What a horrible situation for her.
As for the "loving" jws who threatened you with the life of your son, please be advised that threat has been used for over 100 years now. So far, no one has lost a baby to Armageddon.
And good for you for standing by your husband and listening to his reasoning! There are so many good and decent men here who have been abandonded or at least ignored by their wives who are under cult mind control.
The first book you should probably read is Crisis of Conscience by Ray Franz. He was a governing body memeber who resigned and then was later df'd for eating lunch with another brother who da'd. Please note that this punishment came before it was a WT rule to shun those who da'd themselves. Anyway, it will give you an honest look inside the organization. Probably the second most reccommended book is Combatting Cult Mind Control by Steven Hassan. He was never a jw but escaped the clutches of the Moonie cult. Now he teaches therapists about how to treat former cult members.
Until you can get your hands on those books and others, just go through this list of eight criteria for mind control listed below. Think about how the critieria fits into the life of a jw. Then everytime you have anxiety about Armageddon or any of the other threats used by the Watchtower cult, read that list again. It will help you to overcome your fears with logic.
http://www.csj.org/studyindex/studymindctr/study_mindctr_lifton.htm
Once you wrap your head around the WT being a cult, you'll be free to explore all kinds of religious beliefs. I hope your husband joins us here. In the meantime, I'm sending you my contact information via private message. Just click on the blue envelope in the upper right hand corner of the screen. Click on the message. You'll get an error message, so use the back arrow button, click on refresh and try again.
You and your family are about to embark on living a free life. Congrats!