Phone calls from one side of the family tend to leave me flat and either in tears or pitifully curled around the toilet throwing up from the stress-induced migraine and a stomach in knots. Bad for me in the normal run of things, but pregnant... takes it from bad to nightmarish if I risk a miscarriage. I am trying to do all I can to distance myself, and having a partner who stands strong next to me is a blessing, but my folks know how to push all the guilt buttons and usually manage to drag me back into the family mess after a few weeks/month. It's time to let them go, to accept that I can't be what they demand, and that their misery isn't my doing, it's their own choices and actions. But any spells/prayers/rituals that can help me hold tight to what I know is the right action to take for myself, my husband, and eventually our children would be (possibly literally) a life saver.
You need to start thinking of yourself as a mom right now. From the sounds of it, you have to make a choice between the life and existence of your unborn child or allowing your family to verbally abuse you at every step. A chant that I use when I'm having moments of weakness is "I am the one. I am the power. This is my time. This is my hour." This chant reminds me that no matter how I am feeling, what is going on around me, or what other people are doing to me that I am the most powerful person in my universe and nobody can take that power away from me.
Screw your biological family. Screw their guilt, and screw their abusive behavior. Look to your strong partner and the family made of close friends who support you. We often have a stronger bond with the family that we choose than the family we are born into.