Well, I feel sorry for your situation, but I don't. think there's anything anyone here can tell you that wasn't already brought up in the other thread.

1. You need to leave Singapore within a month.
2. There is only one way to get to the US, pretty much the only place you can go.
3. This flight has a number of issues which heighten your already tense feelings about air travel.

Those are the facts and we can't change that, so you have to find a way to cope with them. Since you (understandably) do not want to take medication, have you considered seeing a therapist in Singapore who can perhaps relieve your anxiety?

I know it won't help you, but the A350 is an incredible aircraft and, to paraphrase what I said in your other thread, it doesn't know that it's nighttime, or that it is over water.