body shape and weight :(

Hi, well I was never a large child or someone too skinny, I was average. When I went through puberty things changed. My body shape changed and I gained quite a lot of weight and not in the 'its just natural' thing. I'm not obese or anything but I feel large and and full compared to the other females in my family. Whenever I see them its a constant reminder that I'm large and have an ugly body.

Some may say I look average, not overweight but not skinny but I have stretch marks on the side of my stomach which makes me feel sick looking at how much I've changed in four years. My friends tell me I'm fine and try to make me feel better but my family is a different story. They don't mean to make me feel bad but sometimes some of their comments that they say in my presence are very hurtful. It's not that I haven't seen myself; I know what I look like, but it hurts that other people say it and think that as well and would say it out loud without thinking that maybe it's a touchy subject to me. When a family member or elders say that (who aren't related to me) I stay quiet and act as if I'm not bothered but there's a good chance I'll have a cry in private about it. I can't tell them that because it'll just seem like I'm making a big deal about a little thing when in reality its quite a few things that add onto each other. I've lost hope in dieting, does anyone have any advice in motivation to lose weight or ways they avoided food and felt better about themselves. Every time someone says something regarding my weight I tend to comfort myself in food which makes things worse.
Please help, i'm 15 years old and i have no idea what to do.