HELP!

Carrot1971

I've been at the same weight (give or take a pound) for about a month now. I've tried increasing my calories from 1200/day to 1500/day for an entire week. When I went back down to 1200/day I lost 1 pound almost immediately and its remained stagnant again. I work out at least 3 times a week (various strength training DVDs and eliptical). I have lost 23 pounds to date and only have about 10 left to go. I know the last 10 are always the most difficult but I'm beginning to get discouraged. I don't want to stay at this weight for the rest of my life but am beginning to think my body just won't release the last 10 pounds. Any suggestions?