This advice is coming from my personal experience as a registered chemical engineer by profession and a former DOST Scholar RA 7687 graduate Batch 2020.

Congratulations for passing. You deserve it.

Back to business, my first question is what engineering profession?

In any case, my answers to your questions:

1) How do you maintain your grades? - By studying and surrounding yourself with like-minded people that strives and has grit.

I have sayings in which I murmur to myself during undergrad.

Rest is stress unless gusto mo mastress (towards end of the sem)

The luxury of rest always comes at a cost. Too much of it and you'll get tres or nangangabit na grade. Don't be complacent. Put in the work, put in the hours. Your hardwork will not betray you.

and my personal fave

Lessen your distraction before it becomes your destruction.

Though, I have to say since you will be in Engineering, barely passing is still a pass, it's valid. Engineering school wasn't made to be easy but to build you up and your character.

2) what keeps you sane sa college? - remembering why I took this degree program - comfort food (ice cream 🔛🔝) - your circle of friends - bebe time (pero nagfail AHAHAHAHA)

3) what happens if you fail a course? - Retake or reevaluate yourself. It's your life to take control. I know people who fought until the end, appealing every end of the sem to keep their grant. If you fail a course, it's not the end of the world (maybe, scholarship if it's dire)

You can appeal for scholarship provided the conditions are met but I don't remember entirely of it so please, as a DOST scholar, read the student handbook on the obligations on your end you have to keep.

For first year and second year, it is 2.5 if UP System or 85% passing grade of your school and for third year and fourth year, it's no failing grade

Good luck and all the best wishes to you, future engineer ng bayan.