Help! struggling on cd

ive been on cd since 7th jan ive lost 31lbs,the last month i have stayed the same,i lose a couple of pounds then put them on ,ive really been struggling ,i started back on sole sourse last week doing really well then bang cim weekend blow it, so still at same weight,which is good in some respect as im maintaining what i am, but i need to lose 2 to 3 more stone im 14st know, by my records i should be nearly there but because im struggling to stay with the diet its not happening and its wasting my money.so need sum advice to get me on track anyone been wer i am.