The superficial answer is, "Stop worrying". Once you put I am (not) sure/certain, I think/believe/suppose/etc in front of a statement, you change the whole dynamics. Deal with will/going to as one issue. Deal with any introductory words as a separate issue.
"Paris is the capital of France" is presented as a fact.
"I don't think (that) Paris is the capital of France" is the expression of a doubt about the presented fact.