That's what chemical depression looks like, I believe. Situational depression is based on a situations that make you depressed. Chemically based depression requires chemically based treatment. There is no shame in going to see a doctor and getting medicine to help address this challenge. Sometimes to "get over it", we need to get help…and sometimes that help is in the form of medicine.
I tried for years to "overcome" my ADHD symptoms by "trying" to change my behaviors and impulses and by "toughing it out" and setting unrealistic goals and expectations for myself so I could change. But once I got on proper medication and my brain chemistry was managed, my symptoms were reduced in a way that all the trying in the world never could have done. Then, I was able to see much more clearly and live a better life.
So, you might be onto something. Situationally, you may have nothing to be depressed about. But chemically, you are depressed. I think it's important to go see a doctor and look into the possibility of using medicine to help treat your symptoms of depression (which may only be for a season to help you stabilize).