How do I stop feeling overwhelmed by security systems and hardware?

Security systems and hardware are a big field, with a lot of parts and a lot that can go wrong, so feeling overwhelmed is an honest reaction, not a sign you cannot do this. When everything is new at once, the mind sees only the size of the mountain. That is a trick of the beginning, and it eases as the pieces start to become familiar. The way out of overwhelm is almost always to shrink the field. You do not have to understand every system and every component to be good at your work. You need to master the ones you actually handle, one at a time, until each stops being a source of dread and becomes routine. Depth in a few things beats a thin, anxious grasp of everything. Pick the single system or piece of hardware you meet most often and focus there until you truly know it, then move to the next. Let the rest wait. Competence is built in a line, not all at once, and each thing you master makes the whole field feel smaller. The overwhelm is not permanent. It is just what the start looks like before the pieces come into focus.