When my brain was younger and I was going through my first real programming gig/hazing ritual I felt largely the same. I was lucky to have a boss that let me go at my own pace and build up from small self contained procedural scripts, to several related classes, to practicing design patterns by writing my own datase abstraction layer and dB access objects, then controllers, then templating scheme, and by the time I was done “practicing” I was only halfway lost and broken when I jumped into a sprawling framework that handled all this for me :-)
It is just exercising your short term memory that hurts your brain and causes all that stress and you’ll get better. Soon all those layers of abstraction and the way they relate will be more muscle memory. Like driving. You’ll “glance at your mirrors” when merging and it won’t seem so stressful. It just takes time and practice
Also, stackoverflow is man pages for programmers