Hey Amanda! I'm 5'4" and was up to 150 when i found this forum. I have lost 5 pounds over the last month and am looking to loose another 15. I am a little older than you (35 - okay, a lot older!) but can try to help keep you accountable if you would like.
Sometimes I feel as if I too have been dieting for the past 4 or 5 years. It seems as if I spent every winter going up to 145 and every summer getting back to 135. It can be so frustrating.
Try to keep busy over the weekends. Last weekend was the first one in about 2 months that I didn't go crazy and eat everything in the house, so it can be done
I think lifting weights will help. I *hate* it too, but as of October 1st made a promise to my self to spend at least 20 minutes, twice weekly, with weights. I think it is helping - one of the ladies at my job commented yesterday on how toned i was looking.
Just remember, you lost the weight before, and you can do it again!