I believe some psychologists define introversion and extroversion today by how you "recharge". If you found sitting at home reading or watching movies relaxing, then you're introverted. If you feel relaxed going out and spending time with people, you're extroverted. That isn't to say that introverted people are quiet or extroverted people are leaders, but it's simply how they feel after the activities they do. Heck, I lead an improv troupe. It involves a lot of instruction and talking to a crowd of people, but after we're done I can't wait to sit home and breathe.
So what I want you to do is ask yourself, if you're not quite sure, whether or not you're introverted or extroverted. There are some people that are neither, and they're called ambiverted (like ambidextrous. Ambi- means 'both'). I'm not sure how they get their energy. If everything energizes them then they'd probably be used as fuel. Like batteries.
Anyway, it's important to really know what recharges you because maybe you feel tired all the time and you're not sure why. Maybe spending more times with friends would actually make you feel less tired, as crazy as that may sound. It's all relative. If you're struggling with finding your happiness, then maybe it's time to do a little bit of research on what makes you tick. The more you know about yourself the better you can deal with hardships and crazy circumstances.
If you're caught in a situation where your job exhausts you and all your responsibilities compound that, maybe it's time to look into what you can do to change things. If you're extroverted and you're working in a cubicle, and you go home to play video games by yourself or something, all you're doing is wasting all that energy. It all works the other way around, too.
I realize that some responsibilities you can't just 'get out of', but life changes need to be made if what you're doing isn't "working" for you. Why would you go about your life if you're not happy? Why wouldn't you try to change something? If you're not satisfied with where your life is right now, at least look at why you're not happy. Consider what things you do on a daily basis, and whether or not those things contribute to your exhaustion or relaxation.