Re: I think I'm feeling burnout or worse. I am seriously considering walking away.
I'd say that it is time to move on, but to do so in a very careful and thoughtful way. Sometimes we find ourselves in situations that go bad, through no fault of our own...but sometimes, also,we either choose situations that are either bad to start with, or we choose to stay in situations that are headed in the wrong direction. We can't control another person's attempts to be abusive or to create a cult or to train in ways that are harmful to others, but we can control whether we have anything to do with them. That's the part that I think you need to ponder now: what you chose then and why, and how you want to make your choices now.
A lot of things in your post make your situation sound like you really jumped into aikido with both feet, that you invested a great deal of energy into it, and also that you invested it with great expectations -- which seem to have been largely met up to a point. It's quite common for an enthusiastic beginner (not just in aikido but in many other things as well) to surf on a wave of revelations and epiphanies for quite a while. That life-changing energy sure is addictive, much like the energy of a new relationship. But just as with a new relationship, after a while you get beyond the newness phase, and the "birthday" sensation of an endless succession of new gifts goes away. Even in the most non-abusive situation in the world, this will happen. This is when the hyper-enthusiastic beginner has to ask some questions that they may not want to ask, because they may not like the answer.
If you feel that the dojo you're training at has become abusive, you definitely need to walk away. The question is whether you should proceed to walk into another dojo. Your new dojo may not be abusive, but it isn't going to take you back to that newbie-new excitement where you had a new revelation every day -- they're going to come a lot fewer and farther between, and you'll sweat harder for each one. You have to ask yourself if you're the kind of person who can sustain interest and commitment in something that doesn't have those juicy rewards all the time. Most people aren't, to be honest -- this is why martial arts training will always be a minority interest. You may not be in that minority. If that is so. better to accept the fact and simply walk away. It's not a value judgment, just the way things are.
I would also suggest -- and this may be a bit controversial, but here goes -- that you not postpone your decision until after your test. If you are going to walk away from it, be willing to walk away from it now. Don't be one of those students who develops "test tunnel vision" and doggedly trains to the test, all the while ignoring the truth that they really don't want to be there any more. The important test that you are facing now is one of integrity and self-knowledge, and it matters a lot more than 4th kyu.
Best of luck, Travis.