gaining weight while pregnant. ADVICE PLEASEEE

So background. I have suffered from eating disorders since I was in 7th grade I'm now 19, graduated and pregnant. I am so beyond excited and happy to be pregnant and to grow a tiny human. It's just hard to see my weight go up after getting over the disorders and maintaining a healthy/fit body. I was at my goal weight and was toning when I found out I was pregnant.  Does anyone know how to help with this? I've been feeling really down and gross about myself. I am 20 weeks and I know that I've only gained 12 pounds but that's so much to me. Please help with some advice!?