How can I stop the cravings?

I’m having a bad day. Here’s my rant.

I think  the hardest part of my quest to health has been dealing with cravings. I surely don't deprive myself of calories, but I try very hard to make sure they are good calories. But man, it never fails that I have to battle some kind of sweet tooth or salty crunchy craving, and it's like clockwork. Every day.

Usually after lunch I have a sweet craving. This is where a piece of fruit comes in handy. Today, for instance, I brought in some watermelon to eat as my mid-afternoon snack. However, it wasn't long after I was done eating lunch that I felt the need to eat something sweet. Rather than trying to ignore it (which only makes it worse) I ate the watermelon. I figured I'd deal with the lack of a mid-afternoon snack later. (I ate an apple that my co-worker gave me)

And every night after dinner...probably about 2 hours or so after...I get the crunch craving. Pretzels, crackers, Cheez-its (omg deadly) popcorn, blue tortilla chips (love them!) I find myself standing in the pantry searching for them without even thinking about it.

I gave up the Cheez-its, pretzels and crackers all and replaced them with Mary's Gone Crackers (lately I've been eating the Sticks and Twigs version.) I also tend to have the blue tortilla chips on hand for my salsa fix.

I've tried not buying snacks at all...like, not having anything in there for me to be tempted by. That was a big mistake. I ended up getting so agitated that I popped a bag of Dennis' butter popcorn and ate it with anger.

As much as I try, I can't fight the craving. I still, to this day, find myself counting out my portion, rolling up the bag, walking out of the kitchen, eating my portion, and getting my butt up to walk all the way across the house for more. It's like I have some kind of addiction. I've tried all the tricks but can't seem to break the habit. What do you do?

Am I not eating enough throughout the day? What causes these cravings? Maybe I'm missing some kind of nutrient?

Anyway, my training today consisted of 15 minutes of intervals on the elliptical, followed by 15 minutes of run/walking hills on the dreadmill. I'm trying to nurse my quad (even though it seems to be fine but I don't want to overdo it) and I found that the run/walk method with hills is still a kick ass workout. I was at a 5% incline, but when my quad heals I will add more. I think it will help me learn how to properly tackle hills.

How do you deal with cravings? Is there something you crave everyday? Something you feel like you must have?