Hi Franchini - firstly, bless your heart. What a horrible, horrible time you must be going through. I am the OP from the april 2011 thread that BigGlasses referred to (lovely message by the way BG!) so I can speak with some authority when I say that i have some understanding of what you're going through.
My story (in brief!) - found out i was pg with twins at 7 week scan, confirmed MCDA at 11 weeks and was then scanned every 2 weeks. At 20 weeks i was diagnosed with severe TTTS - like yours, 1 of my twins was swimming around in a sea of amniotic fluid and the other had none, no visible bladder and an intermittent/absent heartbeat. I had laser surgery at birmingham womens hosp 2 days later (7th april 2011 9:15am.... I'll never forget!). Long story short, my twins survived the surgery and i came home to lincoln that evening and was then scanned every 2 weeks at lincoln. We had several hiccups - thought to have recurrent ttts so went back to birmingham at about 26 weeks, a brain abnormality (which turned out to be nothing) and reduced movements. All of that meant that on occasion i was scanned every 3 days, sometimes just once a week, right up to when my waters broke at 2am on 20th july 2011 - 35+1 weeks gestation.
So here's the happy ever after: my girls are now 2 years 3 months and as healthy and developmentally 'normal' as any other their age.
There were four of us on the original thread and we ALL had our happy ever afters. We were lucky to find each other and do some virtual hand-holding through an incredibly traumatic and worrying time. Thank god for mumsnet or i wouldn't have coped i'm sure.
If you are on facebook then there is a TTTS uk parents page which is equally invaluable. I would suggest you find any source of support from people who have been through / are going through what you are as they are the only people who will truly understand the lonely feelings of deep sadness and worry you will be having.
And I'm here too if you have any questions or want to talk through how you're feeling.
Wishing you lots of positive thoughts and good luck for everything you will be going through xxx