I get bored really easily but if I get bored I can get really depressed afterwards. Like if I don't do anything productive for a day that night I'll have theses dark feelings that engulf me. Its terrifying. I don't know what's wrong with me and I've had this for a whole but I usually kept myself busy. But recently I have lots of spare time and its has gotten much worse. Does anyone have any advice? I just don't know what to do.

The internet my friend, has loads of things on it.
I suggest Stumpleupon
Or finding ways to help yourself in the future (finance advice)
Gaming
Reading (Light novels, manga, books)
Anime, etc.
I sincerely do not know how you people can get bored easily when you literally have a toybox in front of you with unlimited possibilities.

It sounds like you want to do something productive with your life so you don't feel like you're wasting away, so start helping out in the community. Help out in homeless shelters or make food to give out to poor people ect... There are so many people in need, but people are usually selfish or just don't have enough time. You have the time, so use it.

When I have extra time I usually go to this site: lesswrong.com
Not everyone likes it. In fact I know plenty of people who don't, but it gives you something to think about.
My main advice is to do something extremely time consuming, but not tedious. That would just make it even more boring.