Well... Don't leave your comfort zone.
See, sometimes I think people forget what emotions are for. Among other purposes, they also help fast track certain decisions based on accumulated experiential information.
Comfort exists for a reason, as does fear and anger.
The purpose of comfort, ostensibly, is to tell you when you've found a happy medium between various extremes.
So... sometimes people begin to feel uncomfortable in situations that used to be their comfort zone, and then they blame comfort itself and the message it sent for their new feelings of longing for more and the frustration from their own locked-in habits whose usefulness has expired.
However, comfort itself is innocent in all this... during the time it was most acutely felt, all things were in fact in proper balance. The trick is learning to be adaptive in self-perception to realize when the same situation is no longer comfortable.
SO, what does that mean for you? I think you should chase your comfort zone. Over time, that will expand and lead you to new experiences that wouldn't have been comfortable before.
Sitting around doing the same 'ol won't be comfortable forever, but while it is, that means the deeper, sometimes wiser, parts of your brain have found an equilibrium which is hard to attain... and if you can't find it at a college age, it won't be as easy to find when you're older and more set in your ways.
So when it feels comfortable to socialize, do that. When it's uncomfortable, stop.
When it's comfy to sit around in your PJs studying in private, do that. When you start to feel bored and frustrated, stop.
Sorry for any redundancy, I haven't attempted to explain this particular theory before. In short, trust your instincts and strong emotions - they have valuable insights to share.