Pregnant with depression?

Ever since my husband joined the navy two years ago I have been absolutely miserable. I haven't been able to be happy since day one. I try to support him but every night I'm crying and every day I'm depressed. I am 16 weeks pregnant and I can't be happy at all. Everyday I'm begging that I can get through it because I'm alone. My husband wont be home till next year in december and I'm pregnant with his baby. I have tried everything but it wont go away. I've always have spouts of depression but never to the point where I needed medicine. Now I can barely eat and I can't even admit to anyone how horrible I've felt especially now. No medicine is helping me right now and I don't want to keep going to a doctor who cant do anything else. I love my baby and I love my husband but I just don't know what i can do to atleast help the baby grow. Knowing that i am not able to give this baby everything it needs to grow is just making me feel even worse. I really don't know what to do anymore. I need some type of advice therapy and meds just make it worse not go away. And since I got pregnant it's been a million times worse. Help please