The feeling of nothingness

Been there. Getting out of the house or spending time with friends helps.

I get that feeling a lot, but I fight it with videogames, anime, working, etc.

All the time

I get that feeling when I'm really sore from working out. I don't want to move. lol

Sometimes during the summer when there is nothing to do

If that ever happens for long periods of time, i.e. more than a week or so, then it's probably depression.

That feeling is the feeling of low serotonin and/or endogenous morphine.

Yeah, it's been happening to me a lot more than usual recently, although that's not nearly as bad compared to some of you guys. Hopefully we all get a fresh breath out of life soon to counter act it.

What if that happens only for a few hours?
I'm not sure if the term "depression" is really right for this, I mean in those times i feel like I've lost interest in all things not hope...

I've already reached nirvana.

Depression is definitely more of a "hope" thing. Try to do things that give you energy. With energy comes interest, sometimes.