You've had a lot of good advise here!
I understand the mix of feelings you have for your parents and this situation.
I regard myself as having two sets of parents; the genuinely wonderful mother and father I love, and two people in a high control group.
They will sometimes act in a way controlled by their "programming", rather than one controlled by their real emotions.
They are the victims. They are two victims that royally piss me off at times, but I am the adult, and they are the ones in a high control group.
I had the advantage of "walking away", and waiting long enough before I got divorced so that I could argue (using Society literature) I effectively wasn't a JW anyway, so they logically couldn't df me. I avoid my parent's "hot buttons", and if they preach at me, I either (if its something inconseqential or in passing) ignore it or politely dissemble their arguements until they give up. It's taken a little more than a decade, but now they respect me and really try to avoid confrontation themselves.
I could take a blow-torch to their entire belief structure, on a scientific, historical, Biblical or logical basis. But they always veer away from getting deep enough into it to really undermine their faith. As they are both in their eighties, I see no reason why I should deny them their hopes by forcing the issue - although my dad did once after a few beers, admit that we didn't really know (if there was a god), but he thought he'd rather be wrong and not know it than discover there was a god and that he'd pissed god off. It's called "Pascal's Wager", but of course the idea a hundred pounds or so of human being could piss god off (especially if they lived their life trying to be a good person even if they didn't do x, y and z) is rather silly.
So, I get what you mean on several layers
However, even though you could jump through the Elders' hoops and get reinstated and then drift away, as you are where you are already, I would "stand firm".
You are now living a real life. A difficult one at the moment, but a real one. Going back to fantasy land even though you KNOW it is fantasy land now is not a good idea.
By living well, showing them how happy you are with your life, and how confident and free of "guilt" you are, you will show how silly all the JW propoganda about people who are no longer Witnesses is. This will in time hopefully modify their attitude.
Even if they do carry out with their threat (that the cult makes them do, not how they would act if they were free), it might be worth just doing what you would normally do as a good daughter (in your eyes) even if it is turned away at first, or not acknowledged as it should be. The JW's talk about "winning people over without a word", and it's actually something you can do too.
"Be excellent unto them", to quote Bill and Ted, even if they do act unreasonably.
You can always choose attack as the best form of defence. Many JW parents DO keep contact with DF'd kids. The literature (as I read it) is confusing over whether one HAS to cut off contact with family memebers, and the position has changed to some extent over time. You can actually attack their personal decison to shun you (if they do) and maybe through your arguments, based on Society literature, make them feel they can still be a "good Witness" and see you as they normaly would.
But good luck to you, and well done so far; you're showing courage and brains. People here can advise you, many of us have been down similar paths, and even though there is NOT "one way" to go after leaving the JW's (as reading this board for five minutes will show you), that is part of the joy of leaving a cult.
You become responsible for your own life. Freedom is NOT "just another word for nothing left to lose" (lyric from 'Me and Bobby McGee). Freedom and responsibility are essential to realising the potential we each have as a human being.
One more thing. You shouldn't not go back for your boyfriend. You should not go back for you. I probably don't need to make the point, but it is an important distinction.
All the best
Gyles