FET Twin Loss

I implanted two grade 4AA embryos on August 16th. Levels went from 2300 to 3000, went to the doctor and Baby B sac was collapsing, Baby A had a yolk sac and fetal pole, too early to hear heartbeat. Just had another beta done and it dropped from 3000 to 2900. There was a 4 day gap from those two betas. I have to have an US tomorrow. I feel so defeated even though I am trying to remain positive. I should be about 6 weeks and 4 days. I wish I would have Pgs tested my embryos. I have 5 embryos left, but I’m worried they are abnormal. I don’t even want to try again. I’m 36 and this was my first pregnancy. No cramping or bleeding, this is a horrible experience. I’ve read about vanishing twin, but I know those levels should be rising not dropping. I need some support.