Messed up metabolism

So after much dieting, I'm pretty sure I screwed up my metabolism, because now I have to eat extremely little to avoid gaining weight.  In the past month, I gained 10 pounds, and I'm struggling to get it back off. 

Is there some way to calculate how much our metabolism got messed up or at what level it is at now?  And how can I fix my metabolism without gaining even more weight?

My current exercise routine includes biking over 6 miles every day, walking over 2 miles (on top of day-to-day activities), and doing bit of resistance training (with light weights) occasionally.  I eat a lot of fruit, which I know is bad because I probably eat too much of it (today, I ate 15 frozen grapes, two large bowls of sliced watermelon, one green apple, and a pluot), but I also don't eat that much for lunch and dinner.  I rarely ever eat breakfast (I'm just not hungry in the mornings, and sometimes I just wake up too late for breakfast anyway and it's "lunch" time).

What should I do? 

You're gonna have to gain a little weight to fix your metabolism. The ONLY thing you can do to fix it is to slowly start eating more calories. Good luck, it worked for me. Check out my latest journal entry

Three things to rev up one's metabolism that I have been told by my health-wellness doctor and that I have read on several web sites are:

1. To start your day, drink a large glass of water.  Data charted by the HW doctor indicates in the two groups of his clients, the ones who drank the water in the morning before eating breakfast kept their metabolism burning best.
2. Eat a high-protein breakfast.  It will keep your metabolism going well all day.
3. Have a good protein meal around 30-40 minutes after your hardest exercise workout.

Over a week ago, I deliberately screwed-up my metabolism.  Applying the above criteria, I think I have my metabolism back to normal now.

Maybe I'm crazy, but if you are really working out as much as you say you are every day, you probably aren't eating nearly enough!!! What is your activity level, your daily caloric intake? How many calories do you burn? You need to make sure this is under control first. Its also very possibly that if you do excersize this much, you've put on muscle weight. Have you been taking bodily measurements? Sometimes the scale doesn't acurately represent your progress.