Cystic Hygroma and loss of 1 twin :'(

I underwent a CVS needle biopsy (unplanned) on Tuesday at 12 weeks after my first ultrasound showed the loss of one of my twins and severe swelling and "webbing" (as doc described it) behind my other baby's head/spine. The doctor (a specialist in the field) called this a Cystic Hygroma. Because there was a twin, the NIPT tests (simple blood draw) would throw inconclusive numbers. I'm devastated at both findings. This is my first pregnancy at age 37 & I'm on my own. She told me there is an 80% chance of severe deformities, heart condition, any number of trisomy conditions resulting in the remaining baby not surviving to term or dying within the first few months of life (suffering) and if the swelling continues, jeopardizing my own life. Mourning the loss of one and contemplating the termination of the other has been excruciating. I never thought I'd have to be deciding this. I'm glad the testing will give me definitive answers, but this being my first pregnancy, I am heartbroken. I would never allow my child to suffer needlessly in the short time that statistics show for survival. I'm certainly praying for good news next week but am preparing myself for a heartbreaking decision. Asking for any and all prayers, healing energy and strength and ANY advice or experience with this. Thank you.