What did I do wrong?

As a mother of a child with special needs, I often ask myself 

"What did I do wrong?"

"What could I have done better?"

"Why is my child like this?"

The really shitty thing is that I have no idea what the answer is to any of those questions.  As I reflect back over the past 6 1/2 years, there are definitely events that stick out in my mind, events that could have been prevented, and I wonder...."Is that what caused this?"

The day Nate toppled off the bed was awful.  We had just gotten home from the store, and I was going to set my purse down on my dresser.  I put him on the bed (not even thinking that he'd roll right off), turned around to set my purse down, and from the mirror, I watched him flip right off the bed.  Just like the movies, everything happened in slow motion.  As quickly as I could, I raced over to him, scooped him up, and we both sat on the floor crying our eyes out.  I felt like a horrible mom.  Who the hell leaves their 10 month old unattended on a bed?  He wasn't crawling yet, but he sure as shit was rolling everywhere.  I should have known better.  Did that fall do something to his brain?

At 13 months Nate got a super high fever.  We had just gotten home from vacation, and he started getting irritable.  One morning he woke up with a 103* fever.  I called the doctor, and the nurse like said to just give him Motrin and Tyelnol, and not to worry.  Like a dumb-ass I listened (and who wouldn't- it's a doctors office, right?).  It was the first time Nate was sick, and I didn't know any better.  After the first 24 hours, I brought him in for an appointment, and they said there wasn't anything wrong.  I was told "It's probably just a virus."  His fever lasted for 3 days.  On the 3rd day, I brought him into the office again, and they found the beginnings of an ear infection.  He was given a prescription for Amoxycilin.  Well, we found out the hard way that Nate is allergic to it.  He broke out in an allergic rash all over his entire little body.  If I had taken him to the hospital instead of the doctor, could they have brought down his fever better than Motrin?  Did the fever fuck up his brain? 

Did I not give him enough fruits and vegetables as a baby?
Did I take the right kind of prenatal vitamins?

Should I have given him formula instead of nursing him?

Did something happen during birth that they didn't tell me?

Did I interact with him enough as an infant/toddler?

Should I have read or talked to him more?
WHY DID THIS HAPPEN!?!?!?!

None of these questions can be answered well enough for me to be satisfied.