Since your wedding day is so important and you should be able to enjoy it, your doctor may want to prescribe Xanax or something similar (no worries -- you don't have to take Xanax every day, just as needed). You don't necessarily need to have an anxiety disorder to be prescribed Xanax -- many people have prescriptions for just what you described, stressful, uncomfortable, or fearful situations (like flying). Call the doctor's office and ask to speak with the nurse (who will most likely talk to the doctor him/herself). You may need to visit the doctor for an appointment, but it will be worth it if you enjoy your wedding!
Since you limited your guests to 32, I'm guessing you know these people pretty well. Hopefully that will make the situation less overwhelming! Practice some relaxation techniques, such as deep breathing. If you start to feel overwhelmed at your wedding, just focus on what you practiced to get you through that moment. Since you self-regulate pretty well by finding some quiet space and fresh air, make sure you have a way to do that at your wedding. Could you use another room at your reception site for some alone time? Granted, you don't want to leave your guests for long periods of time, but taking the occasional 5-minute breather won't hurt. In fact, you will probably enjoy your wedding more if you just give yourself 5 minutes every hour or even half hour to stop, collect yourself, and not have a bunch of people looking to talk. Also, use your soon-to-be husband for support! You might feel less stressed if your hubby stays close to you throughout the wedding/reception. At the very least, it will take some of the focus away from you individually.