I am not too sure how i got out of it myself actually... Depression is a complicated topic itself and i don't want to assume anything i say to be true
I think probably one major reason of depression is our hormones, which is responsible for our emotions. They (GnRH) start being produced at around 7 and might subside around 17 years old. For some reason the feeling of too much hormones produced makes you really down, like an extra weight placed onto you.

Stress has been a thing that enhance it very much, due to it we tend to eat junk or bakery food to make ourselves happy.
However, these food enhances these hormones, so probably by eating these, it can keep your stress away for awhile but you won't be able to get out of depression (if you have).

Its good that you know you are depress, because being aware of it can be the 1st step of getting out of it. Because hormones are not part of your brain, and you can technically say that what you are feeling now is not by you, but your body.

Fighting back the feeling seems to be the only way. If you are feeling heavy and sluggish, force yourself to give some impactful punch in the air, scream, stretch, get yourself energetic, dance it off!

---

Everyone is going to feel this feeling, and the mood given by people can affect other people's emotions as well. If you don't want people to snap at you and make you depressed, try to give a smile!
It is hard, its irritating and why should we do it anyways? iTS TIRING.
The feeling of irritation is not by you but your hormone, its your consciousness against your body, and if oyu really want to be able to control yourself, you have to do something and make a difference. Its hard, even I cannot get out of it, but...
Be happy, the only way to get out of depression is to force yourself to be happy, energetic and eat right u v u"