Hard workout followed by not-so-good feeling

Hi all. I am new here (how many times is that phrase written here a day??), so forgive me if this has been answered already. I looked around, but didn't see what I needed. Yesterday, a friend and I planned a 12 mile bike ride, and that was it...

Then, after the ride she says to me, "Hey, lets make this a brick!" So, we then ran for three miles. All of this took us about 2 hours total (I didn't say we were fast!), and my HR monitor was showing very high - around 170-180 during much of the workout. (my avg was 157 - which is about 10 beats higher than I would like it to be)

Because I didn't plan on quite that long of a workout, I didn't plan nutrition well at all, eating a sandwich an hour before departure, and only water during the ride/run. This is my first good lesson.

After getting home, I was fine at first, but then after about 20 minutes, I felt horrible - nauseated and freezing - I took a hot bath to warm up. I wanted to go to bed, but knew I needed to eat. I drank a smoothie, a couple glasses of water, and ate a cliff bar. About an hour later, I ate dinner with more water. I still feel wrong this morning - almost hung over. This seems to be dehydration, but I'm wondering if there is any words of wisdom you all might have for me other than - drink water, stupid!

Any thoughts would be greatly appreciated... I've been training for four weeks now for an olympic distance in September. We are also heavily considering a sprint distance in three weeks. I need to get this under control before then. Thanks in advance! I love this forum!

~JoAnna