O.K. Breezy....take a deep breath...in through the nose.....out through the mouth.
The good news is, if medical school is really what you want, you're in a great position to make it happen. In fact, you're in a way better position than probably 90% of the people on this nontrad forum.
You're young, single and it sounds like you have some passion and the natural abilities required (based on your GPA).
My best advice to you is to take a stepwise approach. Yes, you should definately get some volunteer\shadowing experience. The shadowing will give you an idea what you are getting into. As for volunteer experience, you are young and that equates to inexperience in a lot of people's minds. I'd work on stretching yourself a bit. Step outside of the box that is "normal" for you. Basically that means don't just go volunteer at the local hospital emergency department and pass out blankets and urine test kits. I would shoot for some community volunteer experience that focuses on underpriviledged folks.
You also need to focus on finishing out your prereqs with the best possible grades. Then move onto the MCAT. It's never too early to start studying. Meanwhile, hopefully you have been developing some relationships with the folks that you will be asking for recommendations. You want great LOR's not just decent ones.
These are the main things that you need to focus on, but are not the only things. You're in the right spot if you want advice. The folks here on SDN will give you the tools you need to succeed.
Keep working hard and remember that you're young and have plenty of time to make this happen so don't get discouraged. If you do, just pop back into the non-trad forum and talk with us old farts...we'll square you away.