I'm just a person with Asperger's myself. A professional therapist would likely be much more helpful to you than I would.
One thing I know as a person who has been in relationships is that there's usually a logical reason people stop communicating, even if their logic doesn't make sense to you. I sometimes withdraw from all people due to something going on with a particular person or with me. For instance, perhaps one of my roommates is treating me like her maid, but it makes me withdraw from all human communication in for a few days or weeks. It's not that I'm holding a grudge or giving her the silent treatment, but that her failure to view me as a person like herself, with thoughts and feelings, was deeply disturbing and hurtful. Most of my social effort goes into fitting in, so my motivation to socialize disappears when my earnest attempts to fit in, such as cleaning up after a messy roommate, backfire and result in emotional abuse. It's like finding a landmine in your yard; after that, there's no telling where it's safe to step.