I second CapedCrusader's reply.

Interact with others. It doesn't matter if it's only one person. Just connect. It's cliche, but that's life!

To answer your question, though, here are some of my suggestions:

- Look for a local group of mountain climbers and climb the highest mountain in your place or proximity
- Do some water rafting too
- Go to a peaceful paradise (I'm a beach person)
- Get into a relationship
- Work hard on something you love

Yup, they all need somebody else who you need to interact with.

The way I see all this is: Do whatever you want to do while you're still young. Doesn't matter how you do it (like you may borrow some money just to not miss the perfect opportunity); just find a way and do it. I believe creating nice memories in your "youth" has an effect on your future goal-setting. You better see it as early as now, at this stage of your life. Sometimes, the thing you've done only once is the best.

You may be an introvert (from how you described your routine) but it may not hurt to share your experiences with other people. Sure, you may not really want the interaction at all; but just give it a try.