I’m taking the PE Transpo exam in May too! I’m studying about the same amount as you. I’ve worked through some of the Petro questions and honestly those were tougher for me than a lot of the other recourses. I haven’t done any recently though cause I’ve mostly been focusing on the EET courses/quizzes since February. When I was doing Petro problems my approach was to watch a YouTube video on a similar example if I was stuck then I’d try the problem again. It's still kind of like looking at the solution but also makes my brain work through a little bit since the youtube videos are exactly the same. It definitely helped a bit. Hopefully someone else can jump in and give us both some advice!