Don't worry, you are fine, and you are doing fine.
Now, I just want to add: That this may also be, his personality.
The reason I say this is, I have 2 kids. My Daughter, is like that (not to that extent, but similar to your son), and my son, is NOT at all like that.
They have completely different personalities.
I did not treat them differently.
I did not raise them differently.
So my point is: do not feel bad. It is not your fault nor your total creation of him, that he is this way.
BUT yes, you must teach him, how to be less so like that, AND make sure he does get better at managing himself.
You did not say, how old this son is????
You also, do NOT have to be at his every beck and call.
Gradually, and as he gets older, he should get the point.
Also teach him, to do things for YOU too. For his Mommy.
Teach him about "helping" and being a "TEAM", too.
It is not only... about doing things for HIMself.. but also for you/others. So that he gets the hang of it.
To help him: Just remember yourself, that this is GOOD for him. You are giving him Wings to fly, with.
So, do not get snappy.
This is ALL new to him. He is learning. Just keep at it.
My Daughter is 8.... and though better and though she is in fact very independent, she is still a tad that way.
Again, she is not a bad girl or a selfish girl. She has just always been this way, since she was born.
My son, has NEVER been this way.
AND... my son, was conceived/born AFTER I had had a miscarriage.
But that did not in any way... "make" him more needy/and me more catering to him.
As I said, my son is MUCH more different, than my daughter.
all the best,
Susan