I know where you are coming from because I have been there myself. For those who keep buying, I think we are trying to fill a need for something we are missing in our lives and fabric gives us that pleasure and fills the need.
On the other hand, I had not made a fabric purchase (with the exception of 2 1/2 yds for my ironing board cover) for over 9 months. It was not hard - I simply don't have the money (and will not lie, sneak in, or hide the purchase from my DH or take away from the household budget), don't have the time to make anthing (I am in school full time), and I have more than enough stash to take care of things for quite sometime.
This week I started on my watermelon quilt and I did have to buy a combination of 1 1/2 yds of tans because I did not have enough on hand. It was easier than I thought as I found a new LQS and FQ's were $2.25 ea. The quality of fabric was excellant so I got 8 pieces. I did not need to have anymore.
Today I found another new LQS which is fantastic. She has a wonderful place with all current styles and brands at a reasonable price and, I am so proud of myself - I bought nothing because I needed nothing. I loved many fabrics, fondled them, oohed and ahhed over them, but walked away without buying.
Sometime ago I had to do some 'self-talk' and start asking myself why I was buying, when would I be using the fabric, will I like the fabric in 2, 5, or 10 years whene and only when I get around to making the item, and the big one - Can I afford it??? If you even hesitate for a moment on this one, you do not need to buy it. I have no problem walking away now and I can now enjoy without the guilt and the expense.