I've found that for me the more I shop/spend, the more I want to do it. But if I force myself to stop for a while (even a few days) it seems to jerk me out of my rut and then I don't need to do it so much. It reminds me of sugar- the more sugar you eat the more you tend to crave it, right? But if you restrict yourself eventually you find the craving goes away, or lessens at least.
I did that no-spend August thing and it really helped me to see my spending habits more clearly. At first I just took it a day at a time, but by the end of the month I was on a high from being so careful about spending and not just buying to buy. I was so proud of myself. It was really enlightening. Also getting rid of so many things, selling or donating, has made me realize I don't want to just re-accumulate stuff, it's like a circle that just goes 'round and 'round. So that has also helped a lot. I would try to give yourself a goal- like you won't buy anything else the rest of this month, or this week. Just take it in little steps and see how much you can do. You may surprise yourself.