Feeling guilty for feeling annoyed with my friends

I'm in a friend group right now, and these girls are some of the kindest, the most smartest group of people I've met. But I can't help the feeling but get really annoyed with them sometimes. I don't feel this way about my other friends, it's just them. I realized this has nothing to do with them as a person, it's more of a mix-match. They have their way of rolling along and living life, which is very different from mine and I totally respect. I have more of a work hard play hard mindset, where I would put in work towards my goals and value my future. But I'm also the kind to get burnt out easily, so I'll want to have a night out where I'm dancing the night away, or just quality time with my favorite people and not talk about school work or my future. I noticed with these group of friends is that they are ALWAYS working. Even on the weekends, they show up to the class building and work, which I respect them for. However, it's not the way I roll, and I guess you can say "Well, why don't you just focus on what you do and let them do their own thing?" I do, but my issue is that when you're constantly around these people who has this mindset, and for someone like me this can get very overwhelming. Our classes are very long, lasting almost 5-6 hours, and as someone who has a history of stressing out waaay too much and is trying to do better this semester, it doesn't quite help. What makes this situation worse is that it's not their fault, and I don't blame them. But I'm human, and sometimes my irritation shows, which I try not to do as much. 

I guess my overall statement is that personality wise, I've realized my friends and I are very different, and it may not be the best compatibility with me. They're more introverted, whereas I like to talk to people and be more outgoing. It's almost like I feel out of place, not left out, but just out of place. It's so hard to explain this feeling with words. I mainly feel like I can't be myself around them, and as someone who values self-expression a lot, this kills me. So for the most part, I keep to myself when I'm around them to save my energy. And when I do share a lot, I always regret doing so afterwards. I feel very guilty for feeling this way about my friends who haven't done anything, but on the flipside I also don't blame myself for feeling this way.