I don't have much to add, everyone here has echoed what i felt. I had twins very early (29 weeks), so had 8 weeks of them being in hospital and being looked after PROPERLY by PROFESSIONALS. The minute I got them home, I felt helpless, useless, pathetic and a failure.
For example for the first few days we would take it in turns to be upstairs with them and one or other of us would go out for supplies....if it was my turn to sit with them i didn't go to the loo, i didn't move basically....I would sit and sob wondering how on earth people made it through. Then it twigged, people do make it through, people go on to have MORE kids, so seriously how bad can it be?
It took me a good year to settle down properly, would feel very shaky a lot of the time.....I went back to work when they were 5 months old and I would dread going to pick them up, break into a cold sweat, panic almost. They are now 3, and I would love another! I can vividly remember how shit it used to be, but I also know how differently I would do everything. I have learned so much. (I also stupidly think one would be easier, but know i would have been the same had i had one instead of two)
At the time you are going through it, it's the worst experience of your life, but it really does fade, but I also remember being told the same and hating hearing it, thinking "but it's not fading, they are not sleeping, I can't go anywhere, do anything...." You find your own course, theres no right and wrong, but I can guarentee the minute you do take a deep breath and think I can do this, your little man will settle too. They feed off our angst and its a viscious circle, you get wound up, he gets more shouty, you cry, he's cries, blah blah.
Good luck and stay in touch