Rude SIL & Nosey MIL

So my SIL and I used to be the best of friends for about 4 years. We did everything together, and I could tell her pretty much anything. Flash forward to my engagement, I asked her to be a bridesmaid. She responded with "Why am I not the maid of honor?" I had to explain to her that my childhood friend Anne (not her real name) that resided up north was going to be my maid of honor. This did not sit well with her... I knew my SIL & MIL had narcissistic and histrionic personality disorder so I was somewhat ready for the back lash regarding her rejection. Despite my preparedness, I was not ready for the magnitude of her anger. Two days before I was going to pick out my wedding dress she called me a fat lazy pig, said she was going to physically attack me, slandered my character and lied to everyone we knew. I did not pursue a relationship with her after the fact, and still to this day do not communicate with her unless I absolutely have to. This kind of behavior continues to this day, even though my husband and I have moved 300 miles away. Flash forward to Friday night, we were entertaining guests and I receive a text from SIL saying "you pregnant?" At 8 o'clock at night, out of the blue. I was livid and didn't know how or why she knew we were trying. Yesterday DH and I are in the car and I asked him why she said this... He proceeds to tell me he told his mom that we are actively trying and have been trying for months. Then he informs me that his mother sat the entire family down (nearly 15 people) and announced that I was pregnant. A blatant lie, invasion of privacy, and downright wrong in my opinion. I cried for 12 hours yesterday and cancelled all of my plans because I feel so helpless now. He texts SIL and she begins to argue with him and slander both of our characters. MIL calls and says it's her business and she needs to know these things. I cannot believe what I am hearing and reading from them both. Husband feels guilty and remorseful for me, but does not squash the issue and tell them to mind their own business. I woke up today still so mad and hurt with the bunch of them. What would you guys do? Block their numbers and fbs? SIL is engaged and getting married this summer, how do I get out of seeing her (without divorcing DH lol)? Going on 5 cycles TTC, already worried and distraught over every negative month and test. Rant over.