The transition to reading "real" texts is difficult in any
language, not just Latin. There's a huge difference between reading textbooks sentences which use mostly familiar grammar and vocabulary, and literary texts, which will have complex constructions and use a large variety of vocabulary in unexpected ways. So, a certain amount of confusion is normal!
There are several ways to try to bridge this gap. I don't necessarily recommend working through another textbook, as this is unlikely to challenge you or hold your interest for very long. But I would suggest you might try one or more of the following:
1) I've found that using readers works well for me. These are generally texts adapted for beginning/intermediate students and are a good way to build up speed and vocabulary recognition. Textkit's edonnelly has a great list of downloadable Greek and Latin readers here: http://www.edonnelly.com/google.html
. I've also found that Lingua Latina
is useful for this purpose, and there are some other more recent readers such as Laura Gibbs' Aesop's Fables
2) Look for stuff written in contemporary (conversational) Latin. Fortunately there are still people who have managed to acquire an active command of Latin, and a site like Nuntii Latini will generally more straigthforward language than you're likely to encounter in Cicero. On a similar note, depending on your interests, you might like the Latin Harry Potter, which I've heard isn't too difficult language-wise.
3) Bilingual texts (or Latin texts with commentaries intended for intermediate students). If you're determined to go ahead and plunge into reading actual Latin texts, it's definitely possible, you just need to be prepared for a somewhat slow pace and occasional frustration. Working with a bilingual text can help here, as it saves you quite a bit of dictionary-searching. You do need to have a bit of self-control, though, and refer to the translation only after you've already tried to understand the Latin, as it's easy to get lazy and stop "working" to understand what the Latin is really saying. Texts which include extensive notes and vocabulary are also useful for the same reason.