i have just 3lbs to loose to reach my goal weight

that will mean i have lost 3 stone since january
admittidly i have lost some of the weight quicker than expected due to having the bowel surgery but i'm hoping if i cntinue to eat healthly then it will stay off & i can loose the remaining 3lbs
i do look in the mirror & i have yet to see the new slim me, to me i still look big, i went shopping with Yvonne (chelonia) last week & bought a dress for my holidays Yvonne made me get a size 12 but whilst i was queing (yvonne had gone looking at something) i quickly swapped the dress for a size 14 as i don't see myself as a size 12 i havent even tried the dress on as i know it will be too big sooooooooooo my question is why do i feel like this & how can i overcome this insecruity????