The {-Ha'} in {jotHa'} implies that the subject used to be calm but isn't anymore. {bIt} doesn't have the implication that a previous state is undone. A {rejmorgh} might just be {bIt} at all times, as their ground state of being. Also, while {jotHa'} is glossed as "uneasy", its literal meaning is "un-calm". Possibly it could also apply to states of being un-calm that aren't quite nervousness, such as being angry, agitated, or excited. On the other hand, it's also possible it's a semi-idiomatic use of {-Ha'} that only has one meaning even though it could theoretically mean something else.

But I don't think these are major differences. I think {bIt} and {jotHa'} would both work fine in your example. {woghtaHmo' romuluSnganpu' jIbIt/jIjotHa'.} Something like that.

Something like {tlhoy SaH} "be too concerned about, care too much about" might also work for "worry" in some cases. It seems more like something you would say about someone else's state of mind, though. {woghtaH romuluSnganpu' tlhoy 'e' DaSaH!} "You're too concerned about the Romulans' transgressions!"