It wasn't a choice. It's who I am.
Anyway, back to the topic. The point is, depression is deep and changes the way you interact and perceive the world. If you've come across depressed people, you can usually see that something's different or heavy about them. They aren't quite alive in the same way that other people are. In my own experience (with other people), there's a loss of levity and playfulness.
If you feel that you've lost some levity and joy, then take a little time and ask yourself how you can really make a good adjustment. You seem to already recognize that you don't like yourself, so you can start there. I like to view it like a tactician... there are some moves you'll make that'll only leave you feeling like a fake, which will make you more resentful of yourself. Other moves will have less "noise." Experiment until you find the right moves.
Whether you actually fit the depressive disorder criteria is really irrelevant, I think. If you see a problem, tackle it, regardless of how it's labeled. The strategies people use to combat depression will work to improve your life regardless of whether you fit some technical criteria.