Following what zyzzyva said, it sounds like you're in the transition from being a resume builder to being a passionate science nerd without realizing it. Congratulations- not too many "noobs" (I would use that sparingly, since not everyone around here is a scrublord) reach that train of thought!
I too hit the wall early on in my rookie year when I realized that coasting along as I had in elementary school would keep me on C team. Rather than succumbing to the stress that accompanied that realization, I started working harder but smarter and figured out what made SO fun for me, which was being able to do what felt like real chemistry for the first time in my life. To work smarter, I came up with some modern poetry and mnemonics to remember how to do stuff and figured out how to regimen my study time to go through as much as possible to get to the fun parts sooner. Ultimately, this meant being moved up to B team later that season and being selected as a reserve member when A team qualified for nationals (which I unfortunately had to decline for various reasons.) If you become passionate about what you do, something similar is bound to happen.
That being said, you ought to ask yourself these questions: what makes your SO events fun, and what could you do to get to the fun parts sooner? The key is to figure out what you need to do to get to the fun parts without sacrificing success, so you need to become more disciplined at studying. I understand if you are overwhelmed with Anatomy, since it looks like there is so much you have to learn, so here's a suggestion: make a calendar in your agenda, allotting one or two topics to a week. Every time you have an hour to yourself over the course of that week, go research what you assigned yourself, and learn the material in whatever way is most interesting to you. If you learn to study that way, events will seem much less daunting.
Once you cross the Rubicon by studying events for your own understanding rather than for the medals, SO will feel less stressful. Trust me, it's awesome over here.

Old fart who sort of did things sort of for some schools.