You're right, it's a bummer when you've worked hard and now have to do it again! Even Oprah has lost weight and gained some back and look at all the financial advantages she has available to her.
Something to focus on is that you've done this before, therefore you KNOW you can do it again.
I would take the time you spend losing this weight to really consider where things went wrong and what you could've/should've done differently to have been able to stay at your goal. Let this be a learnig process for you!
Also, you might start "lurking" on the Maintenance Thread and see if you can pick up some great advice from the IP'ers who are currently at goal and making the life choices necessary to keep themselves there. Just and idea!
I wish you the Best of Luck!