Help me, loseit. You're my only hope.

Possibly not my only hope, but I certainly need help. I am overweight. Not obese, not unhealthy, but just chubby. I am 5'8" and I weigh between 105-110kg on the scale (I change from day to day, but still fat!). I have always been a bigger girl but I carry it well thanks to height, an hourglass figure and big bones (that last one sounds like an excuse, but it's a family trait and I'm the only chubby one!). I am most comfortable at about 80kg, but for healthy weight range, I should be about 75. That means I have at least 30kg to lose!

My problem is this: I have a hard time denying myself anything, including food. If I want something, I give it to myself. It could be food, clothes, whatever! When I crave sugar or fat, I give in instantly. This makes it exceedingly difficult to lose weight. I go to the gym 3-4 times a week but you can't out-train a bad diet, no matter how hard you push. When I diet, I start out well for the first couple of weeks and then I stop. I gradually stop doing the right thing and go back to eating crap again. The problem is that now I am miserable. So miserable. I won't let my husband touch me, I can't find anything to wear because all my clothes sit poorly, I always feel uncomfortable and self conscious.

Has anyone ever had this problem and how have you over come it? I appreciate any sliver of help that I can get! The next time I post on here, I want it to be full of awesome before/after pictures!