In my non-expert opinion (working off experience), I’d wager what your feeling is more anxiety than depression.

Sometimes, if you are prone to anxiety, the mind can create scenarios out of the blue and suddenly you find yourself becoming hypersensitive to everything around you and your mind is trying to find a reason for the worry.

So, it latches onto whatever thoughts you may have and begins manifesting a stronger feeling of worry, fear, dread, and it becomes difficult to function, if you don’t know how to calm yourself down, before the spiral, as it were.

As soon as you start to think negatively or feel those unwanted feelings, distract yourself. Do something that you enjoy or just take a few deep breaths to help calm your mind and help you think more clearly. Then you can better recognize whether your worry is merited or not.