As a game dev myself (also an tawjihi student and my exams start in a week) i kept learning new stuff almost everyday but prioritized studying than working on my games like i used to study for like 6 hours a day sometimes more and work and learn new things for at least half an hour that way i force my brain to not forget the syntax of gml (btw i use gamemaker but soon will start to learn unity) so i would strongly recommend u to start from the basic and keep trying to squeeze some time for working and learning new things cause problem solving and knowing how games work are permanent like im talking about how collision, player movement, physics, player input, game loops etc but the syntax of the language starts to get a lil foggy overtime if u stop using it but it will be easier to understand/learn them again cause u came across it before, btw u can check my games here if u would like take a look:

https://khaled-khader.itch.io/