I am an only child also, of course I had all the attention, it is normal for a parent to channel his Unconditional love to his child. But still, I know how to share, give attention, and about the jealousy...everyone has it...it is a feeling and it matters how you controll it and act...a big part that is named mature or adulthood...or better yet...responsibility.
So...the rest that is saying other wise, may think twice :)