Please help..

I'm 18 years old. I have been going through so much with my weight since I was very young. There had been times when I was very young that I would go in the bathroom and look at myself for what seemed like hours and think..why am I so big and ugly? Everyone seemed to have all the negative things to say..but no one seemed to have positive/helpful things to say. Family and "friends".. When I started dating and finally got a little more confidence about myself and who I am my mom knocked me down again. We where together about a month and my boyfriend came over. I'm not sure what was going on but I was in the back and she was talking to him and I heard her say "Tell fat girl to come here" and he laughed..it was embarrassing and hurtful. I cried myself to sleep that night. And every now and then she calls me big or chunky or whatever to describe my weight. I've had these 2 rolls in my neck since about 5 or 6 that won't go away even at my slimmest. My "friend" and I was at work and I made me a sandwich on break and she tells me that I'm big.. She asked to touch my neck and said " you've had that lil roll since we where kids". I'm very unhappy with my appearance and I have no one to motivate or help me because the talk down on me constantly. I think that has made me eat my feelings the past year. Within a years time 17-18 I've gained so much weight that absolutely none of my clothes fit. I look pregnant and get asked when I'm due ALL the time..and my health(asthma) is getting so much worse. I also have problems with digestion and chronic constipation. I'm 18 years old, 5'0, and 189 pounds. It doesn't seem that big and I know I'm not huge but I'm so unhappy and It's been this way from a very young age..i don't want to feel this way anymore..I need some help.