RAVEN- I agree with what Sir 82 said in, " What you should do depends on what you want ". Exactly.
You mentioned that your JW mom is already shunning you. So ask yourself if you are willing to accept that outcome. Only you know how close you are to your mom- or if losing her in your life is something you could handle- or not. It's your decision.
You could deny, deny, deny that you've done anything wrong but if you told your mom you are living with your boyfriend, the elders are going to keep hounding you until they get an answer. They are really good at NOT recognizing our personal boundaries. As Sir 82 mentioned, they are " trained that way ".
So as some others have mentioned here like Wolfman and others- if you want them to back off, threaten to get a " cease and desist " order from the police against them or if the harassing phone calls don't stop that you WILL get a restraining order against these local elders and tell them they will be getting a letter from your attorney !
As Sir 82 said, they may DF you in what's called " absentia " and two elders will either report to you that they've decided to DF you and that you have 7 days to appeal the decision before it's announced. I know this because I went through this same thing back in 2007 ( over 4 years after I stopped attending ) and I too had moved 80 miles from where I used to attend !
The difference in my situation from yours is that I never admitted to living with my fiancé before I married her - so they had no proof against me. But they still tried to DF me and I appealed the DFing with a threatening lawsuit letter AND I won my appeal ! They did NOT DF me. They called WT legal and WT legal told them to " leave this alone " and they overturned the disfellowshipping.
So you have to get tough with them. I had to go to an appeal JC meeting with 6 elders and stood my ground claiming innocence. That is key. You have to keep claiming you are innocent. Which may be difficult if you already " confessed " to your JW mom.
So it's up to you how much you want to hassle with these guys. If your relationship is important with your mom, you can try to appeal, but there are NO guarantees- especially if you've already admitted to it. Or- You could just ignore meeting with them and threaten legal action from the cops and your attorney- the elders MAY back off, or they may NOT back off. Depends on how tough the elder body is or if they're a bunch of pussies. They may hand over the decision to WT legal and then you'll wait another 2 months or so for your answer ! Believe me- it IS that crazy. Been there, done this.
So you have to ask yourself " how much do I want to emotionally handle "? The water gets deep, it gets rough, it's no walk in the park. The ONLY reason I fought my case was I still wanted to not be DFed so I could talk to my older JW mom, AND still talk to my JW adult daughters to try in time to reach them and get them out of the cult. If I was DFed - none of them would listen to me.
So I've tried to portray all the options here- good and bad, but bottom line it's your decision, everyone's circumstance is different. Just presenting options and eventualities here. I wish you the best of luck ! We are always here as a support system for you, O.K. ? Take care, and hang in there, Peace out, Mr. Flipper