Overly sensitive?

For those that have children or work with children; how do you deal with your child that is overly sensitive?

My son will be 2 years old in April and I feel he's overly sensitive. It is so frustrating some times. I never experienced this with our daughter so its totally new to me.

When you tell him, "No." it is as if you have crashed his entire world. I'm not kidding. His bottom lip basically touches his knees and the look in his eyes is heart breaking!

Lets not forget the tears and the cry that goes along with that. That is like the icing on the cake.

It doesn't matter how you say no or what you're saying no to, it is the end of the world for him when he hears it.

There are times he'll come to me, lip out, tears falling, crying and screaming and demand to be picked up. By demand he'll stand with his sad face staring at me and his arms up in the air waiting until I do pick him up.

I of course pick him up to comfort him but some times I'm in the middle of things that he has to wait a moment and it makes it worse.

Any tips or tricks on how to prevent his world from crashing when telling him no or keeping him from doing something he shouldn't be doing??