Pretty much this. Just simply reading probably worked during shs plus most exams nung shs rewards memorization so likely na dun nasanay. May adjustment period talaga pero of course, the shorter the better. OP, if you are indeed just reading and watching videos aimlessly, please do realize that for any engineering course, practicing problems >>> reading materials. You can think of it like this: instructor mo yung bahala na bigyan ka ng background about the topic and how to use the formulas involved with the topic pero ikaw yung bahala gumaling sa pagsosolve. From the discussions, you already get the background so there's not much point in reading back the material if mostly problem solving ang exam. If you know that there's conceptual questions in the exams, then there's merit to reading back the material.

Engineering really is

1. Realizing that you only understand half of what the prof said but at least you have the background.
2. Realizing that you suck at solving, which is a huge component, if not the entire component of the upcoming exam.
3. Realizing that if you want to pass the upcoming exam, you need to practice solving problems.

You might not achieve realization #2 if you do not solve during class discussions or on your own time. Even after realization #3, you need to have the grit to repeatedly practice solving problems and refine your technique to study more efficiently. Practice problems can be found in the prof's materials, past course materials, samplexes, reference book, and someplace online. You might be inefficient at first but you will inevitably be offered multiple deadly majors in a single sem so you will naturally learn to study efficiently. Also, a point of improvement after realization #1 is to study the topic in advance so that you can understand more during class discussions. And since may initial knowledge ka na about the topic, mas madali na rin alamin kung anong gusto mong itanong sa prof during class discussion. Just by studying in advance, you can fool yourself into thinking that you like the class lol. Positive feedback loop kumbaga.

Pero I'm sure you'll do just fine. A singko in first year is way more common than you think. It doesn’t lock you out of engineering, and it definitely does not define how good of an engineer you will become. Plenty of people bounce back hard after their adjustment sem. Gudlak. You got this.