Take a look at the original sentence again:
Neil's day revolves around sugar, he anticipates
the pastry he will choose for breakfast, the candy bar he will eat for lunch,
and the ice cream he will have as dinner.
You wanted to fix it this way:
Neil's day revolves around sugar, but he
anticipates the pastry he will choose for breakfast, the candy bar he will
eat for lunch, and the ice cream he will have as dinner.
A good way to fix a comma splice is to add a coordinating conjunction like but. When you use this method, however, you must choose a coordinating conjunction that logically connects the two main clauses. In the example above, but is an illogical choice because you are not showing contrast.
You might want to consult the rules for fixing comma splices and fused sentences.
Go back to the sentence to try again.