Chris good for you! I applaude your decision.
I did something fairly similar in November last year. A friend of mine mentioned that she made a commitment with another friend that they would not buy any new fabric for 1 year. They would allow themselves to only buy batting and thread. When she told me I thought "are you completely insane!!!!". However, after thinking about it for 6 weeks I thought - you know - it's really not such a bad idea.
So I made my own commitment, and shared it with my craft groups (they hold me accountable). No new purchases EXCEPT, for thread, batting, and fabric to FINISH tops.
I think I've done very well. I gave myself a day off, giving myself permission to purchase when a local quilt show was in town (we have only 1 big show a year - where "outside" vendors can sell their fabrics, etc). Even then - I only bought 1 fat quarter, and 1 jelly roll. Quite restrained (well I thought so).
Other than that I've been "good" for 5 months now.
I'm trying to focus on those WIPs. No real reason to buy new fabric when there are so many projects on the go. The only exclusion I've had was/is for my mothers quilt (which I'll write about soon).
Anyway, I wish you well - I know you can do it.