Call myself a little lucky in that I never had to take Paramedic exam as a CBT, mine was on paper... That being said, I have taken the NCLEX-RN and that evil, spiteful CBT exam can easily be one of the most difficult you'll ever take precisely because it is adaptive. With these exams, they will be very straightforward. This doesn't mean they will be easy. A strategy I used when taking the NCLEX was actually fairly simple, and I passed at minimum questions. Unless it is explicitly stated, each question is to be considered by itself. The questions before and after have no bearing or link to your currently prompted question. So, you only must concentrate on ONE question at a time. Read the question (don't look at answers yet) formulate an answer based off what you read. Then look at the given answers. See if one or two match what you were thinking. DON'T ANSWER THE QUESTION YET. Go back and re-read the question while keeping the answers in mind, look for any key words or phrases that support or refute an answer. It is this re-read that helps prevent you from misreading the question. Now re-read the answers and make your selection. Incidentally, you might find that there's an answer that perfectly matches how the question is commonly misread. Once you have made your selection, submit it and move on. DO NOT CHANGE AN ANSWER UNLESS YOU HAVE A VERY GOOD REASON TO DO IT. YOUR FIRST ANSWER IS USUALLY THE RIGHT ONE.
Also, any possible answer that has you going "this is the right answer when (some zebra happens)" is also going to be the wrong one. I call that one the "yeah, but..." answer. It's going to be complex, the real answer will simply answer the question. If you're doing the "yeah, but..." or "what if they mean this..." and it's a tangent away from the question, you're overthinking it.
Any "Select all that apply" or "SATA" questions are basically fancy True/False questions. In order for a given answer to "apply" the ENTIRE answer must be true. If that's the case, select it and read the next line. If ANY part of the answer is false, the entire answer is false and must not be selected. Read the next line. You might have to read 4 or 5 (or more) possible answers to a given question. You could have 1 right answer, a few, or all might be correct. It doesn't matter: each answer must be independently considered T/F in relation to the question. Once you've gone through all of them, click submit and move on.
If your questions are getting harder, that's probably a good thing. These exams WILL find your weaknesses. Once you're at your individual level, expect to get about 50% right... that's because you answer correctly and it gets harder. Answer incorrectly and it gets easier. It'll waffle between those. The hardest thing is realizing that adaptive exams aren't about getting a grade. It's not about getting a certain percentage right/wrong. It's all about whether or not you were able to provide answers to questions that are above passing standard. That's it. If your answers are all above standard, you pass. If you're asked a really hard question and you get it wrong, but that question was WAY above passing standard, that's OK as it found your limit. If all your answers are correct but the difficulty level of those questions is below standard, you fail, even though you might "technically" scored an 85% of the questions asked because you weren't able to get above standard.
If your exam stops at minimum questions, you either easily passed or miserably failed. There's no middle ground. If you go beyond minimum, even if it's ONE question, that means you were somewhere close to passing standard (above or below) and the system has to ask you another question to conclusively determine if you meet pass or fail criteria. Once you meet a rule that stops the exam, the exam will be done and it'll be sent to be officially graded.
While the NCLEX exam isn't the Paramedic exam, it is adaptive, so use those steps above to evaluate each question you're presented. If you're getting good scores in the reviews and you passed the class, you likely know the material. Trust that, just don't overthink it.