Is a size 6 for someone that is 5'5" overweight or something?

I weigh a lot, around 165lbs... but I'm a size 6. I posted that somewhere and someone was telling me that I'm "overweight" and I need to drop 10lbs... but if I drop 10lbs, then I'll probably end up being a size 4 or 2... and that's just nasty. I was 10lbs smaller last summer and I looked like a bobble head; I looked ill and my brother went around telling everyone that I was anorexic (lol).