My depression is getting severe but I don't know how to tell my family.?

I am 19 years old and I'm suffering from depression badly. It started in my early teens when my family problems got severe. My step dad had adopted me and then my mom went to prison so he remarried and his new wife didnt like me so he relinquised his rights and my grandparents adopted me. I didnt see my sister for four years, and by then our relationship was ruined. I struggled so much because he cut me completely out of his life and he was the only dad I ever had. Things got better with therapy and I stopped my anti-depressents (with docs ok) and I was ok until two years later. Now its bad. My doc just prescribed me anti-depressents a week ago but I have yet to take one yet I cant say why. I am married but my husband and I are temporarily living 4 hours away because of work situations and we see each other just once a month, which is a big part of my deep sadness. When we see each other everything is great but we struggle with just talking on the phone its not enough and we fight (not serious fights, just bickering). All the same I miss him so much. On top of that I lost my job and am stuck back living with my grandparents. I've put in fifty applications and nothing. I am supposed to start community college this fall but I'm not sure I can even afford that. On top of that my grandmother (whom is like my mom to me) had a quadruple byp surgery last year, a brain hemmorhage four years ago, and skin cancer three times last year is struggling emotionally and mentally and I worry for her. I feel so hopeless right now and I do nothing but cry. But I'm afraid to tell my family or my husband because they hear me laugh and joke and smile but its all a front and I'm not sure they 'll understand how deep my sadness is. I feel so confused some days I feel pretty good...not content or happy but ok...others I feel like my whole life is going to collapse. I don't know what to do. Any advice?