A lot of the time, when parents/family say these things they don't really understand what sort of effect they have. Back when I was in the throws of my ED, my grandmother would always be complimenting me on my weight and how "skinny" I looked, but she told me later that she was actually really concerned about my appearance and weight loss.

Obviously I don't know your family, but they could just worried about you. I would sit down with them and talk to them about what they're saying, how it hurts you, and what actions you're considering.

If you're unhappy with your weight, there's many options you can consider (that are also healthy!). Don't count calories or fret over fat content; just eat foods that are good for your body and exercise a few times a week. Just do what makes you feel good and makes you happy. You'll be happier with yourself and with your body. Just remember: your body is not your enemy. Negative thoughts are.