Im sick of tring to lose wight but i still want to slim down?

I just want something i can stick with, I'm 4'11 155 pounds size 10. In the last year i have gain about 20 pounds eating almost the same food i always have iv tried every diet under the sun, hell iv even starved for a week but as we all know i gained back that wight in 3 days and then some. I work out about 1hr a day and I also do yoga 3x a week, I don't understand. Iv have done the 6 meals a day, i did the south beach, wight watchers, jenny, atkins, and then some yes some of them do work but nothing sticks. is there something wrong with me that i can't lose wight and keep it off or am i alone?