I found in Gaffiot "sollicitus" meaning agitated, but I think this agitation would have a link with the fact of being worried.
The Gaffiot explains:
Sollicitus = (constantly) agitated, a move without rest, (first meaning)
Mare sollicitum (agitated sea)
Sollicita ratis (a buffeted boat)
Second meaning: full of anxiety, worried.
My theory is that the meaning of this word was first applied to innert things, like the sea and the boats, or whatever, and not to human beings, so it was the literal meaning.
Etymology: sollus (“whole, entire”) + cieō (“move, stir, shake”)
And later, as often, this literal meaning of being agitated, applied to a person, became the synonym of being agitated by the worries. It's the figurative meaning.
But there's no excitation meaning here. It's an agitation, but not from an excitation, but from an anxious state.
But: in the wiktionary, they give:
Thoroughly moved, agitated or disturbed; restless, unceasing.
(of mental afflictions) Troubled, engaged, upset, disturbed, anxious, solicitous; afflicted.
Very careful for, concerned in, punctilious, particular about.
So, you seem to be right, but this meaning of passionated excitation is weird if you see all the other meanings, it definitely doesn't match logically, so, I don't know if it needs a particular context, or if it's late Latin or whatever. Sometimes words change their meaning throughout their history.
Sollicitus • thoroughly moved, agitated or disturbed; restless, unceasing, troubled, engaged, upset, disturbed, anxious, solicitous; afflicted, excited, passionate, very careful for, concerned in, punctilious, particular about • from sollus (“whole, entire”) + cieō (“move, stir, shake”)
Concerned and worried are not exact synonyms, but, in my opinion "concerned" should be accepted here, for sollicitus, as there is no context!
I don't think there's a specific Latin word for concerned, and a specific one for worried, both are Sollicitus, regarding of the negative agitation given by the anxious state.
Quoting this page:
I am concerned about her.
What does this mean? This means that the person is distressed by another individual and feels an urge to do something about it.
I am worried about the ceremony
Worry, on the other hand, is when an individual feels uneasy or anxious about something or someone. Worrying is considered as a negative quality because it only puts the individual in a worse position where he would be thinking over and over about a particular issue, without addressing the possible solutions.