Was it hot outside? Do you wear sunglasses? How long did you ride? Try shorter rides, find a bike path in the forest preserves with shade. Also make sure you stay hydrated.  Did you eat correctly? lack of food can give you a headahce, but I'm not a doctor, I only play one on TV.

I usually get headaches when it's very hot out and I'm riding for hours. Be sure to have plenty of fluids, cold are best and take some headache remedy that works best for you. The neck pain can be eased by putting your head down(look at the road) for a few moments. Be sure you aren't too close to another rider and keep your elbows a bit loose and be sure your shoulders aren't hunched up. Sometimes you have to think about being relaxed. Biking is supposed to be fun!

I recently switched to a new helmet and I too experienced some minor throbbing/headache issues. I do rides that last 4+hours fairly regularly, but w/in the first hour of ridng wearing this new helmet, I noticed unusual throbbing in my head. Realizing that this is nothing to take lightly, I stopped w/ frequency to make minor adjustments to the new helmet and have ended up ultimately getting the fit dialed in so that these problems went away.

   The adjustments included chinstrap-length changes; below-ear buckle tweaking; and also very minor tweaking to the roc-loc apparatus (it's a giro helmet) in the back of the head.

   It was really amazing to me that these seemingly minscule changes to the helmet seetings made such a huge difference in how my head felt.

    Not sure if this might be of help to you too, OaklandGirl, but if your helmet is as new to you as you say cycling is, it might be worth stopping every few miles to make these minor tweaks & make sure your helmet isn't impairing bloodflow anywhere as my new helmet apparantly was. 

  Cheers and Ride Happy!!!