Why is my appetite gone from my depression?

I have been severly depressed for about a month and a half now, with the loss of my boyfriend of 2 years and the death of my grandpa who i was very close with. my boyfriend left me for another girl and it completely ruined my life and plans and dreams, he made me believe we would go forever and i fell for it. my grandpa was my best friend and he was the wisdom in my life. but now i havent been able to eat at all, when i got depressed in the past, it wasnt this bad and i usually ate more, and gained a few pounds, took meds, and got over it. this time is horrific, i use to be 145, and now i am down to about 120 - 125 its like when i put the food to my mouth, my stomach is churning, and i feel like vomiting, my mouth is dry and i just hate the sight of food. im still really upset and seeing my psychiatrist every once in a while, but im busy. my heart is still very heavy and i constantly feel like im going to vomit my heart out of my mouth. when i took ritalin a few years back, i had this feeling, when i looked at food, i was never hungry, food made me sick, and my mouth was dry. its scary cause im losing weight. and i dont know what to do. help?