Number 1 is incorrect. It is highly likely is correct.
But apart from that, they both sound unnatural to me.
It is highly likely that a year from now you won't be worrying (or worried) about it. If you insist on using the going to construction, you'd still be better to make the worry continuous or adjectival: you aren't going to be worrying about it, or you aren't going to be worried about it.