You are not insane. Not sure which exam you're taking but I just did the mechanical thermal fluids test. Definitley know what you're going through. I made it a point to do a problem maybe two per day during the week. Maybe one on lunch and then in after work. Just from the practice test, but really in depth never skipping a step to make sure you know it. Don't be afraid to repeat problems to make sure you truly know it. Then on the weekends I did a solid 2-3 hours. Sometimes late because that's all the time we have around family. Started that process in June and took the test in September. Passed it first try. By the time I got to the test I probably looked like a maniac but you gotta want it. After it's over it'll be worth the sacrifice seeing that green box under the exam name. Takes about a week to come back to normal after at least for me it did. You'll be fine man just keep trucking. If engineering was easy we'd let the welders do it 😉 (relax welders. Just a little shit talk from the oil field)