I've been in the same position, some of the answers posted will help but only in the way a bandaid helps - it's a temporary solution and just keeps your mind a little more interested. The real problem isn't up there, it's in your body.
You need to do something physical outside of work that you enjoy (everyone has one, you just need to find it). Sitting in front of a computer all day is TERRIBLE for your body, you have to move, build some muscle, get your blood flowing. For me it's rock climbing, I had the same issues as you - I love programming and coding but it just wears you down if that's all you do then you go home and say watch T.V. or play video games or just lounge. That's means your body is in a constant degrade and isn't doing what it was formed to do. Your body and your mind are one and the same, you need to use your body as much as your mind - at first you'll have low energy because you haven't been using your body in so long but after a bit (not even that long, for me 2 weeks going climbing 1-2 times a week) you'll find you have a ton of energy, your mind works better, and you are more efficient at your job and your social skills and everything else.
Get hiking, biking, climbing, swimming, push your body past where it's degraded and you'll get it back to where it was before. As a college freshmen your body is still insanely adept and fit and grows - you were probably walking around a lot, moving from class to class, maybe you biked to class or walked to school - all of this ontop of being younger made things easy for you so get your body and your mind back to a balanced state like they were when you were in college. It's that simple.
Diet as well can be a source of this problem and comes down to the same factors - a lot of people in software industries eat a TON of sugar and aren't physically active after (the amount of donuts I've seen consumed is astronomical). It's fine to have sugar, it's fine to eat junk food but you have to use what you are eating, if your not it clunks up your body and slows down not only your physic but also your mind.
All you have to do is be active and eat better and you'll find you have the wisdom of an older person with the energy of your youth.
Have fun, enjoy your body and thus your life.