It's amazing how similiar our stories are! I too, recently decided for my mental health that I needed a break from my mother's craziness. I was pre-warned by my therapist that my break would more than likely go un-noticed, which was right on the money. After 3 months of little to no contact, a major event happened in the family (too long to go into now), which was like a sign from above that the short term break was turning into a permanent one. At least that was my initial reaction. I too have 2 young boys and reacted originally to my parents by making statements like, "Get out the camera and take some pictures of your grandkids, because you surely won't be seeing them anytime soon."
Once some time passed and my initail anger had calmed a bit...Istarted to use the situation to my advantage. The control was once and for all going to be mine. I had no idea what I was going to do or how this was going to begin. But let's just say that my mother did something so profoundly evil, that there was no other alternative but feel utter disgust towards her. Recently discovering that my mother has a disorder, helped me deal with her actions completely differently than I probably would have without being educated about Narcissism. I was scared and felt short of breath and back to being a little girl again when she placed her 1st phone call to my home. However...I handled her differently. I didn't react to her...I kept it together and hung up feeling like I just made a huge step in the right direction.
Remember, you need to start trusting and encouraging yourself that your feelings are real and valid. Regardless of what your mother says or how you respond to her. You need to believe that the ball is in your court now, and demand not only from your mother, but from yourself that things will happen within your comfort and tolerance levels. Just within the past couple of days, I was noticebly aware that with every comment my parents made about whatever the subject was...it's always been "matter of factly", if they say it...I'd go with it. I just realized I don't agree with them and spoke up and didn't care if they accepted my opinion and left the conversation giddy that I had my own thought and still felt the same way after speaking to them. Your mother knows why you have a problem with her...because you've probably been spelling it out for her for forever. Stop giving her the finished puzzle....let it be her turn to put the pieces together. She unfortunately won't be able to do it, but it's time to stop requesting her to "get" what she more than likely never will. If you can come to a peace with that....you'll find you might even be able to have a relationship with her that you'll be comfortable with. It's like mourning a death. But you must remember that happiness is around the corner with a rebirth- a better, healthier, happier you. You can do it! Good luck!