My wife and I have both taken the written test twice without a problem. (Twice because our written expired between written and practical tests - and therein lies your problem) Yes, there is some detail, but it is easily mastered. You just have to pass.
Now the practical test - there's where the fun lies. We tried to get ours done in Livingston (Escapees) and that was a bust. You have to call at 0800 exactly and get on the list. No appointments, no do overs. After trying that for several days, we blew that pop stand with our Arkansas licenses (you don't turn them over until you get your Texas version) and in Arkansas there is no weight restriction for motorhomes.
We ultimately took our tests in Dimmit (look it up) because the local tester would schedule. Most of the larger offices don't appear (or did not then, two years ago) to want to do that. At the bigger DMV's, you are going to have to fight traffic, stuff yourself in a parking lot, and then manhandle all that going back out for the test. You can beat those odds.
Tip #2 - the advantage of a small town like Dimmit is wide streets and low traffic. Do not use a steering wheel spinner! Both hands on the wheel at all times.
Tip #3 - be prepared to do an air brake test with bleed down (maybe you are not a diesel?)
Tip #4 - there are those who say you will have to parallel park - can't speak for them, but the tester was asked that and she looked at me like I had two heads. "Where would you parallel park that monster (38'ft DP at the time)?"
In the practical, drive slowly, have your head on a swivel, signal every turn way ahead of time, and imagine yourself passing with flying colors. If you handle your rig fine now, you'll be fine in the test. Otherwise, do a little practice and get really smooth. They want you to know how big you are, where you fit in traffic, and that you have the confidence to stay out of trouble. If you can't turn a corner without curbing and using the lanes correctly, you are going to have a problem in a tight testing environment.
My bride is extremely proud that she got a higher score because I went first, used the spinner, and got pointed off. She had the advantage of my test, so let the better driver go first.
You will be fine, just be confident and prepared.
Kim