I'm a quitter!

I am hungry today.
I'm not really sure why, because I've eaten enough. But I am dying for desert tonight.
They say it take twenty days to start a new habit. I guess technically it is only day 6 for me. Maybe I'll make myself a cup of tea or something.
I wonder sometimes if the end result will be worth it. Will I actually be able to lose enough weight that it will matter? I mean, I have to lose something in the neighborhood of 80 pounds.  I'm 35, will be 36 this year. Am I too old to expect to be successful?
What if I stick with this, suffer the hunger pangs and deprive myself of the goodies I love...and end up only losing the same 10 pounds or so I always lose and then gain back again. I am so tired too. I feel like I could sleep for a week. I haven't excercised because I just can't muster the energy. I know if I was thinner, I would feel better, healthier. But the whole getting there makes me feel worse.
To top it all off I am very crabby and my husband is bearing the brunt of it. My head hurts and I am using all of my willpower to smile and play with my son. I don't have enough in me to fake it for my husband. Maybe it's withdrawls.
I feel alot like I did when I quit smoking. BTW- it's been 4 years since I've smoked a cigarette and I still want one every time the weather turns warm enough that I could be sitting out on my deck and smoking while sipping on a glass of wine. It took several times for me to finally quit. I had to learn that under no circumstances could I ever give into a craving. What would inevitably happen is that I would be out with friends at a bar or something and one of my girls would like up and I would ask for a drag. Then I'd bum a cigarette or two. Before the night was over I would be volunteering to go on a beer run just so I could pick up a pack of lights. Then because I had just purchased a pack I would have to finish it before I quit again, and before I knew it I was smoking again. It took meeting my husband, who hates cigarettes, to finally quit for good.
I am trying to apply these same lessons to quitting sugar. You know, I never used to believe in the whole food addiction thing. I was like - how can you be "addicted" to food? You have to eat to live! Now I'm realizing that it's much more complicated than that. Some foods cause certain chemical reactions in our body, and those chemicals need to detoxed from our bodies in much the same way that drugs or alcohol or nicotine or caffeine is detoxed from other addictions.
One good thing is that I know that some day it won't be so hard. Just like when I quite smoking, I can expect a day that the gnawing craving for sugar will become a minor fleeting thought that I can brush aside. One day I'll be better. But today- this really sucks!