Lack of weight gain

My doctor isn't upset yet, but will be if I don't gain 10 pounds in four weeks. I was sick a lot my first trimester and I'm convinced I lost weight. I'm 17 weeks now and have only gained 1 pound according to the doctors. 
I eat breakfast and lunch and snack all day (apples, nuts, strawberries, protein bars) and eat a large dinner. My husband is really upset about the lack of weight gain. I don't mind gaining weight but I'm full constantly because of my snacking. I even eat in the middle of the night!
What advice can I get other than eating junk, I don't want to end with diabetes from going crazy trying to gain weight. I'm not a meat or egg fan, I've been trying really hard for the baby on upping my protein.